\u00a0<\/span><\/h3>\nThe researchers were able to confront this challenge by utilising an advanced simulation method known as \u2018first-principles quantum Monte Carlo method\u2019 that finally overcame the obstacles other methods could not conquer.<\/span>\u00a0<\/span><\/p>\nThe team\u2019s findings have been published in <\/span>Physical Chemistry Chemical Physics<\/span><\/i>.<\/span>\u00a0<\/span><\/p>\nHowever, the researchers stressed that overcoming this challenge did not merely come down to developing better simulations: \u201cGetting an answer that does not agree with the experimentally known value is, in itself, not surprising. The agreement can improve with more careful, and more expensive, simulations. But with disiloxane, the agreement actually becomes worse with more careful simulations,\u201d explained Dr. Hongo.\u00a0<\/span>\u00a0<\/span><\/p>\n\u201cWhat our method has achieved, rather, is good results without much dependence on the adjustment parameters, so that we don\u2019t need to worry about whether the adjusted values are sufficient.\u201d<\/span>\u00a0<\/span><\/p>\nThe scientists compared the first-principles quantum Monte Carlo method with other standard methods, including \u2018density functional theory\u2019 (DFT) calculations and \u2018coupled cluster method with single and double substitutions and noniterative triples\u2019 (CCSD(T)), alongside empirical measurements from past studies. The three techniques mainly varied in their sensitivity towards the \u2018completeness\u2019 of basis sets, which is a set of functions employed to define the quantum wavefunctions.<\/span>\u00a0<\/span><\/p>\nTweaking the amplitude<\/span>\u00a0<\/span><\/h3>\nThe team <\/span>found<\/span>discovered<\/span> that for DFT and CCSD(T), the choice of basis set impacted the amplitude as well as positions of zero amplitude for the wavefunctions, while for quantum Monte Carlo, it only affected the zero amplitude positions. This permitted the researchers to tweak the amplitude in a way that the wavefunction shape approached that of an exact solution.\u00a0<\/span>\u00a0<\/span><\/p>\n\u201cThis self-healing property of the amplitude works well to reduce the basis-set dependence and lower the bias arising from an incomplete basis set in calculating the bending energy barrier,\u201d added Dr Hongo.<\/span>\u00a0<\/span><\/p>\nWhile this is an exciting development, Professor Hongo highlighted the wider implications of the discovery: \u201cMolecular simulations are widely used to design new medicines and catalysts. Getting rid of the fundamental difficulties in using them greatly contributes to the design of such materials. With our powerful supercomputers, the method used in our study could be a standard strategy for overcoming such difficulties,\u201d he concluded.<\/span>\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"Researchers from the Japan Advanced Institute of Science and Technology have solved a previously perplexing materials science problem with a supercomputer and quantum simulations.\u00a0 Comprehending the structural properties of molecules in nature or synthesised in laboratory is fundamental to materials science. As science and technology have developed over the years, this challenge has also evolved, […]<\/p>\n","protected":false},"author":13,"featured_media":17855,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24615],"tags":[833,793],"acf":[],"yoast_head":"\n
Supercomputer and quantum simulations solve materials science problem<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n