I want to do single point energy calculations in VASP for $\ce{Mg2Si}$ so what should be initial steps to do? What are tags required in INCAR sufficient to do this calculation?

I would appreciate any help.


I assume that you have relaxed your geometry structure. The single point energy calculation also called the self-consistent field calculation (SCFC), the central quantities outputted by it are:

  • Total energy
  • Charge density
  • Wavefunction

In particular, the charge density and the wavefunction are the two key quantities to perform non-self-consistent calculations, such as band structure, the density of states so on.

A general INCAR for SCF in VASP can be:

    ISTART=0        #startjob: 0-new 1-cont 2-samecut
    ICHARG=2        #charge: 1-file 2-atom 10-const
    ENCUT=450       #energy cutoff in eV
    EDIFF=1E-5      #stopping-criterion for electronic upd.
    NELM=300        #nr. of electronic steps
    ISMEAR=0        #part. occupancies: -5 Blochl -4-tet -1-fermi 0-gaus 0 MP
    SIGMA=0.01      #broadening in eV -4-tet -1-fermi 0-gaus
    IALGO=38        #algorithm
    #LREAL=Auto     #Auto for large cell, False for small cell

    #Magnetic and SOC related tags
    #ISPIN=2              #spin polarized calculation (2-yes 1-no)
    #MAGMOM=15*0 17*0     #initial magnetization
    #LSORBIT=.TRUE.       #switches on SOC and sets LNONCOLLINEAR= .TRUE.
    #SAXIS= 0 0 1         #quantisation axis for spin
    #ISYM=0               #symmetry: 0-nonsym 1-usesym

    LCHARG=.True.         #create CHGCAR
    LWAVE=.True.          #create WAVECAR

If you want firstly to relax the structure, you should add the following tags:


You can check the meaning of each tag in INCAR from vaspwiki.

Hope it helps.

  • 1
    $\begingroup$ Hi Jack, Thank you so much for your help and above answer. $\endgroup$
    – Shalini
    Feb 26 at 7:55
  • $\begingroup$ @Shalini You are welcome. $\endgroup$
    – Jack
    Feb 26 at 19:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.