mylifecg的个人博客分享 http://blog.sciencenet.cn/u/mylifecg

博文

VERY BAD NEWS! internal error in subroutine IBZKPT:

已有 33476 次阅读 2019-8-8 20:53 |系统分类:科研笔记|文章来源:转载

计算弹性常数时INCAR如下:

SYSTEM=SiP
ENCUT=650
ISYM=0

ISTART=0;ICHARG=2
ISMEAR=0;SIGMA=0.1

ISIF=3
IBRION=6
NFREE=4
NSW=1

EDIFF=1E-6
EDIFFG=-0.01
#NPAR=8

LWAVE=FALSE
LCHG=FALSE

IVDW=1
LVDW=.TRUE.

IALGO=48
NELMIN=4
POTIM=0.1

计算过程报警如下: 

VERY BAD NEWS! internal error in subroutine IBZKPT:
 Reciprocal lattice and k-lattice belong to different class of lattices. Often results are still useful...     168

解决办法:

The message does not mean an error.
The procedure doing the evaluation of symmetry uses a numerical criterion (SYMPREC=1E-5)
to determine which atoms are symmetrically equivalent. When this criterion is too soft
the programm can find "false" symmetry and reports that "reciprocal lattice and k-lattice belong
to different class of lattices." To get rid of this message you can:
1) Switch off the symmetry (ISYM=0)
2) Make the treshold for detecting the symmetry more severe (SYMPREC=1E-8)

注:系统有一定的对称性但不太好,但程序的判定条件较低 (SYMPREC=1E-5,缺省?)而认为有对称,

如果设置上面两项,则需要的k点增多!

在INCAR中添加了SYMPREC=1E-8问题得到解决。




https://wap.sciencenet.cn/blog-3306559-1192944.html

上一篇:submit error (Unknown queue MSG=requested queue not found
收藏 IP: 61.54.105.*| 热度|

0

该博文允许注册用户评论 请点击登录 评论 (0 个评论)

数据加载中...

Archiver|手机版|科学网 ( 京ICP备07017567号-12 )

GMT+8, 2024-11-12 17:13

Powered by ScienceNet.cn

Copyright © 2007- 中国科学报社

返回顶部