简介：Inthispaperweproposedanovelexactfixed-nodequantumMonteCarlo(EFNQMC)algorithm,whichisaself-optimizingandself-improvingprocedure,IncontrasttothepreviousEFNQMCmethod,thetrialfunctionisoptimizedsynchronisticallyinthediffusionprocedure,butnotbeforethebeginningofEFNQMCcomputation.Inordertooptimizethetrialfunction,theimprovedsteepestdescenttechniqueisused,inwhichthestepsizeisautomaticallyadjustable.Theprocedureisquasi-Newtonandconvergessuperlinearly.Wealsouseanoveltrialfunction,whichhascorrectelectron-electronandelectron-nucleuscuspconditions.ThenovelEFNQMCalgorithmandthenoveltrialfunctionareemployedtocalculatetheenergiesof1^1A1stateofCH2,^1AgstateofC8andtheground-statesofH2,LiH,Li2,H2O,respectively.Thetestresultsshowthatboththenovelalgorithmandthetrialfunctionproposedinthepresentpaperareveryexcellent.

简介：ExactquantumcalculationsofreactionprobabilitieshavebeencarriedoutusinghypersphericalcoordinatesforthecollinearrreactionO+HCl(v<1)-OH(v’<1)+Cl.AgeneralizedLEPSpotentialenergysurfacewithabarrierheightof8.12kcal/molhasbeenusedinthecalculations.Accordingtothecalculatedresultswefoundthat(1)thereactionprobabilityoscillateswithenergy,(2)thereactionprobabilityshowsvibrationaladiabaticity,althoughitispoorerthanthatforsymmetricreactionCl+HC1.Theanalysisofresonancehasalsobeendone.ThereactionrateconstantsandaveragecrosssectionshavebeencalculatedbyTST-CEQmethod.TherateconstantsareinagreementwiththatbyQCTandsmallerthantheexperimentalone.Finally,thethresholdhasbeenestimatedandisingoodagreementwiththatoftheliterature.