Hello, developers
I want to use the command “coul/long”, Hence, I run a test first to know it.
I chose to simulate a bulk alumina with coulomb interaction. To eliminate the interfere from lj/cut
I set the coefficients of pair_coeff lj/cut to 0.0. The boundary conditions of alumina is “p p p”.
The following is the input file and the data file:
INPUT FILE:
#Lammps 3d Al2O3
log Al2O3.log
atom_style charge
units metal
boundary p p p
read_data al2o3
pair_style hybrid/overlay lj/cut 10.0 coul/long 10.0
pair_coeff * * lj/cut 0.0 0.0
pair_coeff * * coul/long
kspace_style ewald 1.0e-3
velocity all create 1.0 277387
thermo 1
thermo_style custom step atoms temp press pe ke etotal pxx pyy pzz pxy pxz pyz lx ly lz
timestep 0.005
run 2
DATA FILE:
LAMMPS data file
120 atoms
2 atom types
0.0 8.241 xlo xhi
0.0 9.516 ylo yhi
0.0 12.990 zlo zhi
Masses
1 26.98
2 16
Atoms
1 2 -2.0 1.263 4.029 3.248
2 2 -2.0 5.383 1.650 3.248
3 2 -2.0 4.010 4.029 7.577
4 2 -2.0 8.130 1.650 7.577
5 2 -2.0 2.636 1.650 11.908
6 2 -2.0 6.757 4.029 11.908
7 2 -2.0 0.000 1.458 3.248
8 2 -2.0 4.121 3.837 3.248
9 2 -2.0 2.747 1.458 7.577
10 2 -2.0 6.868 3.837 7.577
11 2 -2.0 1.374 3.837 11.908
12 2 -2.0 5.494 1.458 11.908
13 2 -2.0 2.858 1.650 3.248
14 2 -2.0 6.979 4.029 3.248
15 2 -2.0 1.484 4.029 7.577
16 2 -2.0 5.605 1.650 7.577
17 2 -2.0 0.111 1.650 11.908
18 2 -2.0 4.232 4.029 11.908
19 2 -2.0 2.858 3.108 9.742
20 2 -2.0 6.979 0.729 9.742
21 2 -2.0 1.484 0.729 1.083
22 2 -2.0 5.605 3.108 1.083
23 2 -2.0 0.111 3.108 5.412
24 2 -2.0 4.232 0.729 5.412
25 2 -2.0 0.000 3.300 9.742
26 2 -2.0 4.121 0.921 9.742
27 2 -2.0 2.747 3.300 1.083
28 2 -2.0 6.868 0.921 1.083
29 2 -2.0 1.374 0.921 5.412
30 2 -2.0 5.494 3.300 5.412
31 2 -2.0 1.263 0.729 9.742
32 2 -2.0 5.383 3.108 9.742
33 2 -2.0 4.010 0.729 1.083
34 2 -2.0 8.130 3.108 1.083
35 2 -2.0 2.636 3.108 5.412
36 2 -2.0 6.757 0.729 5.412
37 1 3.0 0.000 0.000 4.575
38 1 3.0 4.121 2.379 4.575
39 1 3.0 2.747 0.000 8.905
40 1 3.0 6.868 2.379 8.905
41 1 3.0 1.374 2.379 0.245
42 1 3.0 5.494 0.000 0.245
43 1 3.0 0.000 0.000 1.920
44 1 3.0 4.121 2.379 1.920
45 1 3.0 2.747 0.000 6.250
46 1 3.0 6.868 2.379 6.250
47 1 3.0 1.374 2.379 10.580
48 1 3.0 5.494 0.000 10.580
49 1 3.0 0.000 0.000 8.415
50 1 3.0 4.121 2.379 8.415
51 1 3.0 2.747 0.000 12.745
52 1 3.0 6.868 2.379 12.745
53 1 3.0 1.374 2.379 4.085
54 1 3.0 5.494 0.000 4.085
55 1 3.0 0.000 0.000 11.070
56 1 3.0 4.121 2.379 11.070
57 1 3.0 2.747 0.000 2.410
58 1 3.0 6.868 2.379 2.410
59 1 3.0 1.374 2.379 6.740
60 1 3.0 5.494 0.000 6.740
61 2 -2.0 1.263 8.787 3.248
62 2 -2.0 5.383 6.408 3.248
63 2 -2.0 4.010 8.787 7.577
64 2 -2.0 8.130 6.408 7.577
65 2 -2.0 2.636 6.408 11.908
66 2 -2.0 6.757 8.787 11.908
67 2 -2.0 0.000 6.216 3.248
68 2 -2.0 4.121 8.595 3.248
69 2 -2.0 2.747 6.216 7.577
70 2 -2.0 6.868 8.595 7.577
71 2 -2.0 1.374 8.595 11.908
72 2 -2.0 5.494 6.216 11.908
73 2 -2.0 2.858 6.408 3.248
74 2 -2.0 6.979 8.787 3.248
75 2 -2.0 1.484 8.787 7.577
76 2 -2.0 5.605 6.408 7.577
77 2 -2.0 0.111 6.408 11.908
78 2 -2.0 4.232 8.787 11.908
79 2 -2.0 2.858 7.866 9.742
80 2 -2.0 6.979 5.487 9.742
81 2 -2.0 1.484 5.487 1.083
82 2 -2.0 5.605 7.866 1.083
83 2 -2.0 0.111 7.866 5.412
84 2 -2.0 4.232 5.487 5.412
85 2 -2.0 0.000 8.058 9.742
86 2 -2.0 4.121 5.679 9.742
87 2 -2.0 2.747 8.058 1.083
88 2 -2.0 6.868 5.679 1.083
89 2 -2.0 1.374 5.679 5.412
90 2 -2.0 5.494 8.058 5.412
91 2 -2.0 1.263 5.487 9.742
92 2 -2.0 5.383 7.866 9.742
93 2 -2.0 4.010 5.487 1.083
94 2 -2.0 8.130 7.866 1.083
95 2 -2.0 2.636 7.866 5.412
96 2 -2.0 6.757 5.487 5.412
97 1 3.0 0.000 4.758 4.575
98 1 3.0 4.121 7.137 4.575
99 1 3.0 2.747 4.758 8.905
100 1 3.0 6.868 7.137 8.905
101 1 3.0 1.374 7.137 0.245
102 1 3.0 5.494 4.758 0.245
103 1 3.0 0.000 4.758 1.920
104 1 3.0 4.121 7.137 1.920
105 1 3.0 2.747 4.758 6.250
106 1 3.0 6.868 7.137 6.250
107 1 3.0 1.374 7.137 10.580
108 1 3.0 5.494 4.758 10.580
109 1 3.0 0.000 4.758 8.415
110 1 3.0 4.121 7.137 8.415
111 1 3.0 2.747 4.758 12.745
112 1 3.0 6.868 7.137 12.745
113 1 3.0 1.374 7.137 4.085
114 1 3.0 5.494 4.758 4.085
115 1 3.0 0.000 4.758 11.070
116 1 3.0 4.121 7.137 11.070
117 1 3.0 2.747 4.758 2.410
118 1 3.0 6.868 7.137 2.410
119 1 3.0 1.374 7.137 6.740
120 1 3.0 5.494 4.758 6.740
Here is a part of output information:
LAMMPS (9 Oct 2014)
Reading data file …
orthogonal box = (0 0 0) to (8.241 9.516 12.99)
1 by 1 by 1 MPI processor grid
reading atoms …
120 atoms
WARNING: No fixes defined, atoms won’t move (…/verlet.cpp:55)
Ewald initialization …
G vector (1/distance) = 0.267805
estimated absolute RMS force accuracy = 0.0157593
estimated relative force accuracy = 0.00109442
KSpace vectors: actual max1d max3d = 64 3 171
kxmax kymax kzmax = 2 3 3
Setting up run …
Memory usage per processor = 2.3157 Mbytes
Step Atoms Temp Press PotEng KinEng TotEng Pxx Pyy Pzz Pxy Pxz Pyz Lx Ly Lz
0 120 1 -2381240.3 -4535.5724 0.015381957 -4535.557 -2478725.6 -2478812.4 -2186182.9 2.654582 -90.500739 -1.038697 8.241 9.516 12.99
The keyword Press is -2381240.3 bar, which equals to -238 GPa. I’ve tried ewald. pppm, even coul/wolf. The results are the same.
I think the values should be too large. My evaluation is almost ~1GPa.
My Question is : Is -238 GPa right or not? How to use the command coul/long correctly?
Thanks a lot
Mei Hai