[交流] 【求助】结构优化中，如何选择POTIM？ 已有6人参与

Within all relaxation algorithms (IBRION=1,2 and 3) the parameter POTIM should be supplied in the INCAR file. For IBRION0, the forces are scaled internally before calling the minimization routine. Therefore for relaxations, POTIM has no physical meaning and serves only as a scaling factor. For many systems, the optimal POTIM is around 0.5. Because the Quasi-Newton algorithm and the damped algorithms are sensitive to the choice of this parameter, use IBRION=2, if you are not sure how large the optimal POTIM is.

SYSTEM = Mg-hex
ENCUT = 250
ISTART = 0; ICHARG = 2
ISMEAR = 1; SIGMA = 0.2
NSW = 60; IBRION = 2
ISIF = 3
POTIM = 0.2
EDIFF = 1E-6; EDIFFG = -1E-3
PREC = Accurate

6楼: Originally posted by valenhou001 at 2010-12-23 18:47:48
“改变$i的循环值，再运行run_cell计算一次”
此时$i只附了一个值，就是前面由EOS拟合得到的平衡体积V_0计算(V_0 = 0.5*sqrt(3.0) a^3 * c/a,  c/a的值取自run_cell所设置的，即c/a的值与前一步中run_cell中的 ...