{"id":10,"date":"2016-07-08T10:47:47","date_gmt":"2016-07-08T13:47:47","guid":{"rendered":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/?page_id=10"},"modified":"2023-04-15T09:03:35","modified_gmt":"2023-04-15T12:03:35","slug":"semiempiricos-2","status":"publish","type":"page","link":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/","title":{"rendered":"Desenvolvimento de m\u00e9todos semiemp\u00edricos"},"content":{"rendered":"<p><strong>O problema<\/strong><\/p>\n<p>Um antigo problema em Qu\u00edmica Qu\u00e2ntica \u00e9 o desenvolvimento de conjuntos de par\u00e2metros semi-emp\u00edricos eficientes para uma ampla faixa de aplica\u00e7\u00f5es. Isto nos remete aos c\u00e1lculos pioneiros de Goeppert-Mayer nos anos 30 e ao lend\u00e1rio aparecimento do m\u00e9todo PPP, quando Rudolph Pariser (um qu\u00edmico de pol\u00edmeros que trabalhou na DuPont por mais de 50 anos) percebeu que a integral \u03b3 para uma liga\u00e7\u00e3o CC calculada <em>ab initio<\/em> sobre bases de Slater era muito grande (17,3 eV, maior que o potencial de ioniza\u00e7\u00e3o) e a substituiu por um numero mais apropriado (10,53 eV, a diferen\u00e7a entre o potencial de ioniza\u00e7\u00e3o e a afinidade eletr\u00f4nica).<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-1 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-1 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-1' class='gallery galleryid-10 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon portrait'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/goeppert\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/goeppert-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-1-115\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-115'>\n\t\t\t\tMaria Goeppert-Mayer\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/pariser1\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"140\" height=\"107\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/Pariser1.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-1-114\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-114'>\n\t\t\t\tRudolph Pariser\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon portrait'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/robert_parr\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/robert_parr-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-1-113\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-113'>\n\t\t\t\tRobert G. Parr\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>Devido ao sucesso do m\u00e9todo PPP, nos anos 60 come\u00e7aram a aparecer v\u00e1rias iniciativas dentro da aproxima\u00e7\u00e3o ZDO. Nos anos 70, o grupo do Prof. Michael J.S. Dewar reexaminou a formula\u00e7\u00e3o NDDO e chegou ao m\u00e9todo MNDO. Mais tarde, numa tentativa de se corrigir a descri\u00e7\u00e3o das pontes de hidrog\u00eanio, o grupo da Universidade de Austin adotou uma corre\u00e7\u00e3o Gaussiana nas integrais de repuls\u00e3o de caro\u00e7o levando ao m\u00e9todo AM1. Nos anos 90, Stewart publicou o artigo que o tornaria famoso e v\u00e1rios pesquisadores de outras \u00e1reas n\u00e3o-familiarizados com Qu\u00edmica Qu\u00e2ntica come\u00e7aram a utilizar o m\u00e9todo PM3. \u00c9 interessante observar que esta corre\u00e7\u00e3o Gaussiana <em>n\u00e3o existe na F\u00edsica<\/em>. Finalmente, nestes ultimos anos o grupo de Quimica Fundamental da UFPE em Recife vem corrigindo extensivamente a parametriza\u00e7\u00e3o do PM3. Assim, a obten\u00e7\u00e3o de um grupo de par\u00e2metros semi-emp\u00edricos que seja igualmente bom para geometria\/termoquimica e espectroscopia ainda \u00e9 um sonho.<\/p>\n<p><strong>Justificativa para o uso de m\u00e9todos semi-emp\u00edricos<\/strong><\/p>\n<p>Karl F. Freed (Chicago) examinou extensamente a teoria de Hamiltonianos efetivos. Usando a t\u00e9cnica de particionamento de L\u00f6wdin, \u00e9 sempre poss\u00edvel separar o espa\u00e7o de Hilbert de qualquer problema num subespa\u00e7o <strong>P<\/strong> e outro subespa\u00e7o <strong>Q<\/strong>. Assim, escrevendo-se a equa\u00e7\u00e3o de Schr\u00f6dinger em forma matricial\u00a0resulta num Hamiltoniano efetivo de val\u00eancia dado por<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-2 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-2 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-2' class='gallery galleryid-10 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/freed1\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/freed1-150x150.gif\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-2-2152\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-2-2152'>\n\t\t\t\tKarl F. Freed\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/eff_val_ham\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/eff_val_Ham-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/freed_acr_cover\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/Freed_ACR_cover-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-2-2151\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-2-2151'>\n\t\t\t\tArtigo de interesse\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>mostrando que existe um Hamiltoniano que atua <em>apenas<\/em> sobre o espa\u00e7o de val\u00eancia e mesmo asim fornece os <em>mesmos<\/em> autovalores do problema original. \u00c9 este Hamiltoniano efetivo que os m\u00e9todos semi-emp\u00edricos tentam reproduzir. Segundo o Prof. Alfredo Simas (Recife), os m\u00e9todos semi-emp\u00edricos sempre foram respons\u00e1veis por extender as fronteiras do conhecimento, e eles continuar\u00e3o assim. Tente calcular uma prote\u00edna pequena ou um polissacar\u00eddeo usando um m\u00e9todo <em>ab initio<\/em> e ver\u00e1 ! \ud83d\ude41<\/p>\n<p><strong>A f\u00f3rmula exponencial das integrais de resson\u00e2ncia\u00a0<\/strong><\/p>\n<p>No come\u00e7o dos anos 90, W. Thiel e M. Kolb (Univ. Wuppertal) sugeriram o uso de uma f\u00f3rmula exponencial para estimar as integrais de resson\u00e2ncia ( \u03b2 ) dentro do m\u00e9todo NDDO. O expoente para r adotado foi 1\/2, mas sem maiores explica\u00e7\u00f5es ou justificativas.<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-3 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-3 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-3 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-3 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-3' class='gallery galleryid-10 gallery-columns-3 gallery-size-medium'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon portrait'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/thiel\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"215\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/thiel.jpg\" class=\"attachment-medium size-medium\" alt=\"\" aria-describedby=\"gallery-3-117\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-3-117'>\n\t\t\t\tWalter Thiel\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/resonance_integral_kolb_thiel_eqn\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"242\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/resonance_integral_Kolb_Thiel_eqn-300x242.jpg\" class=\"attachment-medium size-medium\" alt=\"\" aria-describedby=\"gallery-3-2159\" srcset=\"https:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/resonance_integral_Kolb_Thiel_eqn-300x242.jpg 300w, https:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/resonance_integral_Kolb_Thiel_eqn.jpg 486w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-3-2159'>\n\t\t\t\tKolb-Thiel 1991 equation\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon portrait'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/zernerbw\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"191\" height=\"251\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/ZernerBW.gif\" class=\"attachment-medium size-medium\" alt=\"\" aria-describedby=\"gallery-3-116\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-3-116'>\n\t\t\t\tMichael C. Zerner\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>Alguns anos depois, M.C. Zerner e J.D. Da Motta (Univ. of Florida) examinaram a possibilidade de usar a formula exponencial dentro do metodo INDO\/S. Examinaram v\u00e1rias possibilidades para o valor do expoente m ( 1\/3, 1\/2 e 2\/3 ). O resultado desta avalia\u00e7\u00e3o \u00e9 mostrado no gr\u00e1fico a seguir. Os objetivos ent\u00e3o eram obter para a mol\u00e9cula de H2 uma dist\u00e2ncia de equil\u00edbrio de 0,7414 \u00c5, um potencial de ioniza\u00e7\u00e3o de 15,98 eV e uma freq\u00fc\u00eancia vibracional de 4401 cm<sup>-1<\/sup>. Naquele momento parecia existir uma limita\u00e7\u00e3o para esta f\u00f3rmula, pois a freq\u00fc\u00eancia vibracional de 4401 cm<sup>-1<\/sup>. n\u00e3o era alcan\u00e7\u00e1vel (o melhor que conseguimos foi 6200 cm<sup>-1<\/sup> ).<\/p>\n<p>Prosseguimos ent\u00e3o para testar conjuntos de par\u00e2metros para o carbono (Z=6). Todos os m\u00e9todos semi-emp\u00edricos t\u00eam dificuldades em reproduzir as dist\u00e2ncias de liga\u00e7\u00e3o C-C na seq\u00fc\u00eancia tripla &#8211; dupla -arom\u00e1tica &#8211; simples. Nossos resultados comparados com estudos anteriores foram:<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-4 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-4 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-4 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-4 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-4' class='gallery galleryid-10 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/mfig001\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/mfig001-150x150.gif\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-4-119\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-4-119'>\n\t\t\t\tParametriza\u00e7\u00e3o do beta(s-sig) para hidrog\u00eanio\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/mfig002\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/mfig002-150x150.gif\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-4-120\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-4-120'>\n\t\t\t\tErrors in reproducing CC distances for some hydrocarbons. Taken from J.D. Da Motta.\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/dsc00368\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/DSC00368-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-4-121\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-4-121'>\n\t\t\t\tJoaquim D. Da Motta\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p><strong>Progressos recentes<\/strong><\/p>\n<p>Recentemente decidimos explorar\u00a0 em detalhe a reta obtida na disserta\u00e7\u00e3o de 1996. Observamos que o valor do expoente <em>m<\/em> n\u00e3o est\u00e1 restrito a valores positivos. Uma sondagem inicial resultou<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-5 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-5 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-5 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-5 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-5' class='gallery galleryid-10 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/parabola_bottom\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/parabola_bottom-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-5-2147\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-5-2147'>\n\t\t\t\tPotencial harm\u00f4nico\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/extention_2019\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2021\/10\/extention_2019-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-5-2150\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-5-2150'>\n\t\t\t\tExtens\u00e3o da reta de 1996\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/semiempiricos-2\/dsc00368\/#main'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-content\/uploads\/sites\/17\/2016\/07\/DSC00368-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" aria-describedby=\"gallery-5-121\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-5-121'>\n\t\t\t\tJoaquim D. Da Motta\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>Escrevemos um pequeno c\u00f3digo FORTRAN para extrair as constantes espectrosc\u00f3picas de diat\u00f4micas a partir de qualquer conjunto de dados (calculados em qualquer n\u00edvel). Assim apresentamos uma amostra de tr\u00eas pontos na hipersuperf\u00edcie onde obtemos mais de vinte propriedades de H2 .<\/p>\n<table style=\"border-collapse: collapse;width: 100%\">\n<tbody>\n<tr>\n<td style=\"width: 20%\">m<\/td>\n<td style=\"width: 20%\"><strong>-0,7346<\/strong><\/td>\n<td style=\"width: 20%\"><strong>-0,5947<\/strong><\/td>\n<td style=\"width: 20%\"><strong>-0,36812<\/strong><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">\u03b2(1sH), eV<\/td>\n<td style=\"width: 20%\">-0,082715<\/td>\n<td style=\"width: 20%\">-0,076752<\/td>\n<td style=\"width: 20%\">-0,070106<\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">\u03b1(1sH), eV<\/td>\n<td style=\"width: 20%\">-7,61764<\/td>\n<td style=\"width: 20%\">-8,44317<\/td>\n<td style=\"width: 20%\">-10,7482<\/td>\n<td style=\"width: 20%\"><strong>Reference figures<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">Re, \u00c5<\/td>\n<td style=\"width: 20%\">0,74144<\/td>\n<td style=\"width: 20%\">0,74196<\/td>\n<td style=\"width: 20%\">0,74017<\/td>\n<td style=\"width: 20%\">0,74144<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">Be, cm-1<\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\">60,775<\/td>\n<td style=\"width: 20%\">61,074<\/td>\n<td style=\"width: 20%\">60,853<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">we, cm-1<\/td>\n<td style=\"width: 20%\">4401,214<\/td>\n<td style=\"width: 20%\">4401,225<\/td>\n<td style=\"width: 20%\">4401,223<\/td>\n<td style=\"width: 20%\">4401,217<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">wexe, cm-1<\/td>\n<td style=\"width: 20%\">121,339<\/td>\n<td style=\"width: 20%\">121,338<\/td>\n<td style=\"width: 20%\">121,343<\/td>\n<td style=\"width: 20%\">121,336<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">weye, cm-1<\/td>\n<td style=\"width: 20%\"><strong>-0,82<\/strong><\/td>\n<td style=\"width: 20%\"><strong>-0,515<\/strong><\/td>\n<td style=\"width: 20%\"><strong>-0,094<\/strong><\/td>\n<td style=\"width: 20%\">0,813<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">zpe, cm-1<\/td>\n<td style=\"width: 20%\">2179,212<\/td>\n<td style=\"width: 20%\">2179,25<\/td>\n<td style=\"width: 20%\">2178,916<\/td>\n<td style=\"width: 20%\">2179,3<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">G(1), cm-1<\/td>\n<td style=\"width: 20%\">6334,851<\/td>\n<td style=\"width: 20%\">6335,86<\/td>\n<td style=\"width: 20%\">6336,702<\/td>\n<td style=\"width: 20%\">6340,466<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">G(2), cm-1<\/td>\n<td style=\"width: 20%\">10239,013<\/td>\n<td style=\"width: 20%\">10243,62<\/td>\n<td style=\"width: 20%\">10248,795<\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">G(3), cm-1<\/td>\n<td style=\"width: 20%\">13884,426<\/td>\n<td style=\"width: 20%\">13896,9<\/td>\n<td style=\"width: 20%\">13909,55<\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">G(14), cm-1<\/td>\n<td style=\"width: 20%\">33649,57<\/td>\n<td style=\"width: 20%\">34094,28<\/td>\n<td style=\"width: 20%\">34094,67<\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\"><strong>Well depth, cm-1<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">Birge-Sponer (1926)<\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\">39910,8<\/td>\n<td style=\"width: 20%\">39909,1<\/td>\n<td style=\"width: 20%\">38178,9<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">Morse (1929)<\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\">39821,0<\/td>\n<td style=\"width: 20%\">39403,5<\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">Wei Hua (1990)<\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\">41714,6<\/td>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\"><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><strong>\u00a0<\/strong><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%\">De error, cm-1<\/td>\n<td style=\"width: 20%\"><strong>-4964<\/strong><\/td>\n<td style=\"width: 20%\"><strong>+3535<\/strong><\/td>\n<td style=\"width: 20%\"><strong>-2493<\/strong><\/td>\n<td style=\"width: 20%\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u00c9 f\u00e1cil verificar que todas as constantes s\u00e3o obtidas com grande precis\u00e3o, com exce\u00e7\u00e3o da energia de dissocia\u00e7\u00e3o. A descri\u00e7\u00e3o n\u00e3o deteriora quando usamos diferentes isotop\u00f3logos de hidrog\u00eanio.<\/p>\n<p><strong>A seguir<\/strong><\/p>\n<p>No momento este projeto tem tr\u00eas objetivos imediatos:<\/p>\n<ol>\n<li>repetir a procura de conjuntos para outros elementos (come\u00e7ando com carbono e nitrog\u00eanio)<\/li>\n<li>Implementar em nosso c\u00f3digo tratamentos para obter energia de dissocia\u00e7\u00e3o. Inicialmente focamos no m\u00e9todo DPF sugerido pelo Prof. Robert J. Le Roy.<\/li>\n<li>Escrever um c\u00f3digo para examinar espectroscopia de mol\u00e9culas poliat\u00f4micas. Este j\u00e1 est\u00e1 num est\u00e1gio bem avan\u00e7ado, precisando apenas de eliminar bugs.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>O problema Um antigo problema em Qu\u00edmica Qu\u00e2ntica \u00e9 o desenvolvimento de conjuntos de par\u00e2metros semi-emp\u00edricos eficientes para uma ampla faixa de aplica\u00e7\u00f5es. Isto nos remete aos c\u00e1lculos pioneiros de Goeppert-Mayer nos anos 30 e ao lend\u00e1rio aparecimento do m\u00e9todo PPP, quando Rudolph Pariser (um qu\u00edmico de pol\u00edmeros que trabalhou na DuPont por mais de [&hellip;]<\/p>\n","protected":false},"author":19,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-10","page","type-page","status-publish","hentry","post"],"_links":{"self":[{"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/pages\/10","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/comments?post=10"}],"version-history":[{"count":10,"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/pages\/10\/revisions"}],"predecessor-version":[{"id":2736,"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/pages\/10\/revisions\/2736"}],"wp:attachment":[{"href":"http:\/\/www.quimica.ufpr.br\/paginas\/joaquim-motta\/wp-json\/wp\/v2\/media?parent=10"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}