# [Pw_forum] improper symmetry analysis

Kun Yin kyin.cn at gmail.com
Wed Apr 22 10:17:02 CEST 2009

```Thank you for your answers, Paolo and Lorenzo.

First time to know using nr1,nr2,nr3 and nr1s,nr2s,nr3s keywords.^_^

Lorenzo wrote:
> "just make sure that the dimensions of the grids are multiple of the
> numbers of replicas in the fractional traslation."

I don't quite understand this sentence. Just try to increase and decrease
default nr and nrs values as suggested. There are total 9 calculations, 1-3
and 8-0 find symmetry right, 4-7 find symmetry wrong.

[kyin at geohpclab results]\$ grep 'FFT grid:' *.out
temp-1.out:     G cutoff =  744.8786  ( 170271 G-vectors)     FFT grid: (
80, 80, 80)
temp-2.out:     G cutoff =  722.7847  ( 162825 G-vectors)     FFT grid: (
80, 80, 80)
temp-3.out:     G cutoff =  704.6276  ( 156325 G-vectors)     FFT grid: (
80, 80, 80)
temp-4.out:     G cutoff =  689.2743  ( 151669 G-vectors)     FFT grid: (
75, 75, 75)
temp-5.out:     G cutoff =  676.0151  ( 147349 G-vectors)     FFT grid: (
75, 75, 75)
temp-6.out:     G cutoff =  664.3728  ( 143471 G-vectors)     FFT grid: (
75, 75, 75)
temp-7.out:     G cutoff =  654.0170  ( 140255 G-vectors)     FFT grid: (
75, 75, 75)
temp-8.out:     G cutoff =  644.7053  ( 136787 G-vectors)     FFT grid: (
72, 72, 72)
temp-9.out:     G cutoff =  636.2575  ( 134435 G-vectors)     FFT grid: (
72, 72, 72)
[kyin at geohpclab results]\$ grep 'smooth grid:' *.out
temp-1.out:     G cutoff =  297.9514  (  43143 G-vectors)  smooth grid: (
50, 50, 50)
temp-2.out:     G cutoff =  289.1139  (  41151 G-vectors)  smooth grid: (
50, 50, 50)
temp-3.out:     G cutoff =  281.8510  (  39597 G-vectors)  smooth grid: (
48, 48, 48)
temp-4.out:     G cutoff =  275.7097  (  38421 G-vectors)  smooth grid: (
48, 48, 48)
temp-5.out:     G cutoff =  270.4060  (  37309 G-vectors)  smooth grid: (
48, 48, 48)
temp-6.out:     G cutoff =  265.7491  (  36085 G-vectors)  smooth grid: (
48, 48, 48)
temp-7.out:     G cutoff =  261.6068  (  35557 G-vectors)  smooth grid: (
45, 45, 45)
temp-8.out:     G cutoff =  257.8821  (  34621 G-vectors)  smooth grid: (
45, 45, 45)
temp-9.out:     G cutoff =  254.5030  (  34015 G-vectors)  smooth grid: (
45, 45, 45)

For No. 5 calculation, defulat value is 75 and 48. I set nr1=nr2=nr3=80,
nr1s=nr2s=nr3s=50. It finds symmetry right!
when I decrease to nr1=nr2=nr3=72, nr1s=nr2s=nr3s=45. It reports error and
crash.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     task #         1     from  fft_dlay_set  : error #         8      inconsistent number of sticks %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%--Kun YinPh.D. CandidateSchool of Earth Sciences and EngineeringNanjing University502 Geological Laboratory Building22 Hankou RoadNanjing 210093P.R. Chinaemail: kyin.cn at gmail.com----- Original Message -----From: "Paolo Giannozzi" <giannozz at democritos.it>To: "PWSCF Forum" <pw_forum at pwscf.org>Sent: Wednesday, April 22, 2009 3:45 PMSubject: Re: [Pw_forum] improper symmetry analysis> Lorenzo Paulatto wrote:>>> You should not decrease them from their default value, but only increasethem!>> actually the default should be slightly overestimated, so one can try to> decrease it a little bit>> P.> --> Paolo Giannozzi, Democritos and University of Udine, Italy> _______________________________________________> Pw_forum mailing list> Pw_forum at pwscf.org> http://www.democritos.it/mailman/listinfo/pw_forum

```