弹性模量的vasp计算
Contents
1.优化结构
2.计算弹模
INCAR
ENCUT = 600
EDIFF = 1e-6
ISMEAR = 0
SIGMA = 0.05
POTIM = 0.1
LCHARG = FALSE
LWAVE = FALSE
IBRION=6
ISIF=3
NFREE=4
EDIFFG = -0.001
关键参数: 将IBRION=6；ISIF=3；NFREE=4；
不能设置NPAR， 不然会报错：
ERROR
| VASP internal routines have requested a change of the k-point set. |
| Unfortunately this is only possible if NPAR=number of nodes. |
| Please remove the tag NPAR from the INCAR file and restart the |
| calculations. |
弹性矩阵会直接写在OUTCAR里。
计算得到的elastic moduli 是直角坐标下的，只要在同一直角坐标下，不同取lattice，结果相同。测试过diamond的pcell和supercell。
pcell
TOTAL ELASTIC MODULI (kBar)
Direction XX YY ZZ XY YZ ZX
--------------------------------------------------------------------------------
XX 10531.4122 1243.9931 1243.9931 0.0000 -0.0000 -0.0000
YY 1243.9931 10531.4122 1243.9931 0.0000 0.0000 0.0000
ZZ 1243.9931 1243.9931 10531.4122 0.0000 -0.0000 0.0000
XY 0.0000 0.0000 0.0000 5628.7346 0.0000 0.0000
YZ -0.0000 0.0000 -0.0000 0.0000 5628.7346 -0.0000
ZX -0.0000 0.0000 0.0000 0.0000 -0.0000 5628.7346
--------------------------------------------------------------------------------
supercell
TOTAL ELASTIC MODULI (kBar)
Direction XX YY ZZ XY YZ ZX
--------------------------------------------------------------------------------
XX 10534.8952 1243.0926 1243.0926 0.0000 0.0000 0.0000
YY 1243.0926 10534.8952 1243.0926 0.0000 0.0000 -0.0000
ZZ 1243.0926 1243.0926 10534.8952 0.0000 -0.0000 0.0000
XY 0.0000 0.0000 0.0000 5629.8633 0.0000 -0.0000
YZ 0.0000 0.0000 -0.0000 -0.0000 5629.8633 -0.0000
ZX 0.0000 -0.0000 0.0000 -0.0000 -0.0000 5629.8633
--------------------------------------------------------------------------------
Author qiusb
LastMod 2019-01-21