VASP的具体计算流程

VASP的具体计算流程

1!open Files

2!read header of POSCAR file

3!read pseudopotentials

4!read INCAR

5!core level shift related items(parses INCAR)

6!loop over different smearing parameters

7!now read in Pseudopotential

8!LDA+U initialisation(parses INCAR)

10!optics initialisation(parses INCAR)

11!Read POSCAR Startjob and Continuation-job

12!diverse INCAR readers

13!exchange correlation table

14!init all chains(INCAR reader)

15!xml finish copying parameters from INCAR to xml file

16!for static calculations or relaxation jobs DYN%VEL is meaningless 17!initialize the symmetry stuff

18!Read KPOINTS

19!at this point we have enough information to

!create a param.inc file

20!set the basic quantities in WDES

!and set the grids

21!Write all important information

22!write out the lattice parameters

23!write out k-points,weights,size&positions

24!write out initial header for PCDAT,XDATCAR

25!write out initial header for DOS

26!write out initial header for EIGENvalueS

27!initialize the required grid structures

28!allocate work arrays

29!allocate wavefunctions

30!now read in wavefunctions

31!At this very point everything has been read in

!and we are ready to write all important information

!to the xml file

32!initialize index tables for broyden mixing

33!Use a reduced mesh but only if using preconditioning...:

!calculate the structure-factor,initialize some arrays

34!set the coefficients of the plane wave basis states to zero before !initialising the wavefunctions by calling WFINIT(usually random)

35!read Fermi-weigths from INCAR if supplied

36!calculate the projections of the wavefunctions onto the projection !operators using real-space projection scheme or reciprocal scheme

!then perform an orthogonalisation of the wavefunctions

37!partial band decomposed chargedensities PARDENS

38!calculate initial chargedensity if

!)we do not have any chargedensity

!)we use a selfconsistent minimization scheme and do not have a delay

39!========================SUBROUTINE FEWALD ============================

!calculate ewald energy forces,and stress

40!Set INFO%LPOTOK to false:this requires a recalculation of the !total lokal potential

41!some special calculation routines such as GW,MP2

42!++++++++++++do1000n=1,required number of timesteps ++++++++++++++++

!this is the main loop of the program during which one complete step of

!the electron dynamics and ionic movements is performed.

43!reset broyden mixing

!last energy

44!initialize pair-correlation funtion to zero

!also set TMEAN und SMEAN to zero

!TMEAN/SMEAN is the mean temperature

45!this part performs the total energy minimisation

!INFO%NELM loops are made,if the difference between two steps

!is less then INFO%EDIFF the loop is aborted

46!do some check for occupation numbers(do we have enough bands]:

47!Now perform the ion movements:

48!======================FORCES+STRESS ==================================

!no forces for OEP methods(EXXOEP/=0)

!no forces for IALGO=1-4

!no forces if potential was read in INFO%INICHG==4

!no forces if inner eigenvalue solver are used

!check the consistency of forces and total energy

49!we have maybe to update CVTOT here(which might have been destroyed)

50!electronic polarisation

51!add chain forces and constrain forces

52!CYCLE ion!if uncommented VASP iterates forever without ionic upd 53!common write statment applying for most cases

54!do relaxations using diverse algorithms

55!update of ionic positions performed

!in any case POSION should now hold the new positions and

!POSIOC the old one

56!reached required number of time steps

!soft stop or hard stop

!if we need to pull the brake,then POSION is reset to POSIOC

!except for molecular dynamics,where the next electronic

!step should indeed correspond to POSIOC

57!update mean temperature mean energy

58!SMEAR_LOOP%ISMCNT!=0Loop over several KPOINTS%SIGMA-values

!set new smearing parameters and continue main loop

59!tasks which are done all DYN%NBLOCK steps:

60!write out the position of the IONS to XDATCAR

61!acummulate dos

62!evaluate the pair-correlation function using the exact places

!also sum up mean temperatur

63!write pair-correlation and density of states

!quantities are initialized to0at the beginning of the main-loop

64!update file CONTCAR

65!-----write out positions(only done on IONODE)

66!append new chargedensity to file CHG

67!if ions were moved recalculate some quantities

68!WAVPRE prediction of the new wavefunctions and charge-density !if charge-density constant during ELM recalculate the charge-density

!according to overlapping atoms

!for relaxation jobs do not predict in the last step

69!call the ewald program to get the energy of the new ionic

!configuration

70!volume might have changed restet IRDMAX

71!if basis cell changed recalculate kinetic-energy array and tables

72!recalculate the real-space projection operators

!if volume changed also recalculate reciprocal projection operators

!and reset the cache for the phase-factor

73!recalculate projections and perform Gramm-Schmidt orthogonalization

74!wavefunctions are not diagonal,so if they are written to the file !or if we do not diagonalize before the optimization

!rotate them now

!for the selfconsistent update set TOTEN now

!in any case we have to call RSPHER at this point even if the ions do not move !since the force routine overwrites the required arrays

75!update file WA VECAR if INFO%LSTOP=.TRUE.

!or if wavefunctions on file TMPCAR are rotated

76!after10steps rotate the wavefunctions on the file

77!rotate wavefunctions on file(gives a better prediction)

!and read in wavefunctions(destroyed by WAVPRE)

78!next electronic energy minimisation

79!here we are at the end of the required number of timesteps

80!write out some additional information

!create the File CHGCAR

81!Write out the Eigenvalues

82!get current density and write output

83!calculate optical matrix elements

84!calculate four orbital integrals

85!MM:Stuff for Janos Angyan:write the AE-charge density to AECCAR2

86!calculate ELF

87!write ELF to file ELFCAR

88!STM calculation

89!total DOS,calculate ion and lm decomposed occupancies and dos

90!breath a sigh of relief-you have finished

!this jump is just a jump to the END statement

91!here we have sum code to test performance

!Output is written to IUT

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