NEB method

NEB is a traditional method to locate the TS, which works by optimizing a number of intermediate images along the reaction path. Therefore, it’s a computational cost method, while it sometimes can successfully locate TS which can’t be searched by Con-TS method.

Attention

Don’t forget to align the structure first.

GVasp also support the NEB method to locate the TS, just run the command below:

gvasp submit neb -ini/--ini_poscar INI_POSCAR -fni/--fni_poscar FNI_POSCAR [-i IMAGES] [-m METHOD] [-c/--cancel_check_overlap]

Note

The NEB method will construct the reaction path, so one use NEB method must specify the start (-ini/--ini_poscar) and end (-fni/--fni_poscar) structure, while -i, -m and -c are optional arguments.

specify images

Images is the number of intermediate structures between initial and final structures, if you don’t specify, images = 4 will apply.

specify method

GVasp provide two method to control how to generate the intermediate structures.

One is linear, generate structures by linear interpolation from start to end structures.

Another is idpp method, which declares to generate more suitable structures for NEB task, more detailed information can be seen here.

If you don’t specify the method, GVasp will apply method = "linear".

check overlap

Noted that the intermediate structures generated automatically, so some atoms may overlap or closing in some cases, if you don’t check, the NEB task may fail quickly.

Therefore, GVasp check overlap always when you generate the inputs, and this behavior is also its default.

If you don’t like this, you can set -c/--cancel_check_overlap to cancel check, but we (actually I) strongly recommend you don’t do this dangerous action.

Other arguments

Note

More information of other arguments can be seen in optimization task.