常用INCAR文件例子

常用INCAR文件例子1.StaticcalculationsJustremovetheWAVECARfileandstartfromscratch,noparametersmustbespecifiedintheINCARfile.ThedefaultsforISTART=0#startjob:noWAVECARfileICHARG=2#charge:fromatomsINIWAV=1#randominitializationforwf.NELM=40#maximumof40electronicstepsNELMIN=2#minimumoftwostepsNELMDL=-5#noupdateofchargefor3stepsEDIFF=10E-4#accuracyforelectronicminimization2.ContinuationofacalculationInsomecasesitmakessensetostartfromanoldWAVECARfile(forinstancetocontinuerelaxationortocontinuewithanincreasedenergycutoffENCUT).InthiscasejustkeeptheWAVECARfileandstartVASP.Again,anemptyINCARfilewillsuffice.ISTART=1#continuefromWAVECARfileICHARG=0#chargefromwavefunctionsNELM=40#maximumof40electronicstepsNELMIN=2#minimumoftwostepsNELMDL=0#immediatelyupdatechargeYoucansetICHARG=1byhandifanoldCHGCARfileexists.Ifthechargesloshingissignificantthiswillsaveafewsteps,comparedtothedefaultsetting.TocontinuerelaxationfromapreviousruncopytheCONTCARfiletoPOSCAR.3.RecommendedminimumsetupAlthoughthepreviouscalculationscanbeperformedusinganemptyINCARfileitisrecommendedtospecifyafewparameteralwaysmanuallyPREC=Normal#precisionnormalENCUT=300#cutoffusedthroughoutallcalculationsLREAL=.FALSE.orAuto#realspaceprojectionyes/noISMEAR=0or1or-5#methodtodeterminepartialoccupanciesThesefourparametersshouldbepresentinallcalculations.Theycompletelycontrolthetechnicalaccuracyofthecalculationsinparticularthebasissets(ENCUT),andwethertherealspaceprojectionschemeisusedornot.Totalenergiesoftwocalculationsshouldbeonlycomparedandsubtracted,ifthefirstthreeparametersaresetidenticallyinbothcalculations.IdeallytheparameterISMEARshouldbealsoidenticalthroughoutallcalculations(butthismightbedifficultinsomecases).4.EfficientrelaxationfromanunreasonablestartingguessIfyouwanttodoanefficientrelaxationfromaconfigurationthatisnotclosetotheminimum,setthefollowingvaluesintheINCARfile(forbriefnesstherecommendedsetupislackingNELMIN=5#doaminimumoffourelectronicstepsEDIFF=1E-2#lowaccuracyEDIFFG=-0.3#accuracyofionsnottoohighNSW=10#10ionicstepsinionsIBRION=2#useCGalgorithmThiswayonlylowaccuracywillberequiredinthefirstfewsteps,butsinceaminimumof5electronicstepsisdonetheaccuracyofthecalculatedelectronicgroundstatewillgraduallyimprove.IfyouareaslightlyadvanceduseryoucanalsousethedampedMDalgorithm,whichisusuallymoreefficientthantheCGone:IBRION=1;SMASS=0.4#dampedMDPOTIM=0.4#timestepneedstochosenwithcareInthiscase,atoolargePOTIMwillresultindivergence.5.Efficientrelaxationfromapre-convergedstartingguessClosetoalocalminimumthevariable-metric(RMM-DIISalgorithm)ismostefficient.INCARfile(forbriefnesstherecommendedsetupislacking):NELMIN=8#doaminimumoftenelectronicstepsEDIFF=1E-5#highaccuracyforelectronicgroundstateEDIFFG=-0.01#smalltoleranceforionsNSW=20#20ionicstepsshoulddoMAXMIX=80#keepdielectricfunctionbetweenionicmovementsIBRION=1#useRMM-DIISalgorithmforionsNFREE=10#estimateddegreesoffreedomofthesystemNowveryaccurateforcesarerequired(EDIFFissmall).Inadditionaminimumofeightelectronicstepsisdonebetweeneachionicupdated,sothattheelectronicgroundstateisalwayscalculatedwithveryhighaccuracy.NELMIN=8isonlyrequiredforsystemswithextremechargesloshingwhichareveryhardtoconvergeelectronically.FormostsystemsvaluesbetweenNELMIN=4andNELMIN=6aresufficient.6.MoleculardynamicsPleaseseesection9.7.7.MakingthecalculationsfasterUsethefollowinglinesintheINCARfiletoimprovetheefficiencyofVASPforlargesystems:ALGO=Fast#RMM-DIISalgorithmforelectronsLREAL=A#evaluateprojectionoperatorsinrealspaceNSIM=4#blockedalgorithmupdate,fourbandsatatimeINCAR中常用关键词：注释行：SYSTEM初始化参数-电荷和波函数：ISTART,ICHARG,INIWAY电子结构优化：平面波截断动能和缀加电荷截断值：ENCUT,ENAUG电子优化方法：ALGO,IALGO,LDIAG自恰迭代步数和收敛标准：NELM,NELMIN,NELMDL,EDIFF原子结构优化：位置移动方法、步长和步数：IBRION,NFREE,POTIM,NSW分子动力学：SMASS,TEBEG,TEEND,POMASS,NBLOCK,KBLOCK,PSTRESS收敛标准：EDIFFG态密度计算：smearing方法：ISMEAR,SIGMA能量范围：EMIN,EMAX,NEDOS分波态密度：RWIGS,LORBIT其他：计算精度：PREC磁性计算：ISPIN,MAGMOM,NUPDOWN交换关联函数：GGA,VOSKOWN结构优化参数：ISIF等等Smearing方法的选择：总能/DOS计算：k点数目大于4：布洛赫修正的四面体方法，ISMEAR=-5k点数目小于4：Gaussian方法，ISMEAR=0，设置Sigma计算力或结构优化：半导体和绝缘体：同上金属：M-P方法，N=1或2，设置Sigma能带计算：ISMEAR和SIGMA采用默认值不管何种体系、计算什么性质采用ISMEAR=0，并选择合适的SIGMA值都能得到合理的结果线性四面体方法和布洛赫修正的线性四面体方法一定要检验能量收敛情况赝势选择：赝势分类原则如下，根据方法不同有Ultra-soft赝势（USPP）和增广平面波赝势（PAW）根据交换关联函数不同有LDA和GGA（又可以再分为PW91和PBE）根据半芯态处理有X，X_sv和X_pv根据ENMAX的不同有X，X_s和X_h计算磁性材料，所计算体系含有碱金属、碱土金属、周期表左边的3d过渡元素、镧系和锕系元素时推荐采用PAW势。下表列出采用何种PAW以及ENCUT值至少取多少。B_h700B318B_s250C_h700C400C_s273N_h700N400N_s250O_h700O400O_s250F_h700F400F_s250Al240Al_h295Si245Si_h380P270P_h390S280S_h402Cl280Cl_h409Ga134Ga_d282Ga_h404Ge173Ge_d287Ge_h410As208Se211Br216In95In_d239Sn103Sn_d241Sb172Te174I175Tl95Tl_d239Pb98Pb_d237Bi105Bi_d242H250H_h700Li140Li_sv271Be300Be_sv308Na81Na_pv300Na_sv700Mg210Mg_pv265Sc_sv222Ti178Ti_pv222V192V_pv263Cr227Cr_pv265Mn269Mn_pv269Y_sv211Zr_sv229Nb_pv207Mo224Mo_pv224Tc228Tc_pv228Hf220Hf_pv220Ta223Ta_pv223W223W_pv223Re226Re_pv226Fe267Fe_pv293Co267Ni269Ni_pv367Cu273Cu_pv368Zn276Ru213Ru_pv230Rh228Rh_pv271Pd250Pd_pv350Ag249Cd274Os228Os_pv228Ir210Pt230Au229Hg233Ce300Pr252Nd253Pm258Sm225Eu249Gd256Tm257Y