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全部话题 - 话题: kgrid
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J*******3
发帖数: 1651
1
来自主题: Chemistry版 - Question about Kgrid Monkhorst Pack in DFT
Got confused about two concepts:
input file, Matrix of supercell(coordinates) is needed, while when
calculating some properties, Monkhorst Pack is also needed. What is the
difference between them? or they refer to one thing, one is in real space,
the other one in reciprocal space?
Many thanks!
J*******3
发帖数: 1651
2
来自主题: Chemistry版 - Question about Kgrid Monkhorst Pack in DFT
Is there any correlation between them?
many thanks!
R**X
发帖数: 417
3
来自主题: Chemistry版 - Question about Kgrid Monkhorst Pack in DFT
u mean k mesh...thats the place u sample the wavefunction and do integral
J*******3
发帖数: 1651
4
Got confused about two concepts:
input file, Matrix of supercell(coordinates) is needed, while when
calculating some properties, Monkhorst Pack is also needed. What is the
difference between them? or they refer to one thing, one is in real space,
the other one in reciprocal space?
Many thanks!
v****x
发帖数: 498
5

~~~~~~~~~~~~~~~~~~~~~~ this is the system you
want to model
~~~~~~~~~~~~~~~~this is for k-space sampling,
which is used for integration (actually summation)
,
J*******3
发帖数: 1651
6
Is there any correlation between them?
Many many thanks!
v****x
发帖数: 498
7
a large cell ---> small reciprocal cell
so for a large cell, we can use a small k-mesh to obtain a similar accuracy;
for example, when we calculate cubic diamond using the 1x1x1 conventional
cell,
we need a 5x5x5 M-P k-mesh, when we calculate the 5x5x5 supercell, the 1x1x1
K-mech is enough
J*******3
发帖数: 1651
8
Probably it is my misunderstanding. when I read the manual, I got
impression that the matrix of supercell is the transpose of Monkhorst matrix
, is this correct?
v****x
发帖数: 498
9

~~~~~~~yes...
matrix
J*******3
发帖数: 1651
10
Thank you so much!
BTW: I bet you must be an expert in DFT. Any recommending books for
beginner, which would help to be on the track earlier?
Tons of thanks to you!
J*******3
发帖数: 1651
11
Thank you so much!
BTW: I bet you must be an expert in DFT. Any recommending books for
beginner, which would help to be on the track earlier?
Tons of thanks to you!
v****x
发帖数: 498
12
...
For the calculations itself, read the manual, and the references in the
manual
J*******3
发帖数: 1651
13
thanks!
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