[CPMD-list] Energy components in PIMD
Łukasz Walewski
ljw at icm.edu.pl
Tue May 27 12:56:01 CEST 2008
Dnia 2008-05-14, śro o godzinie 12:35 -0400, Axel Kohlmeyer pisze:
Dear Axel,
> BTW: i made a test with BO dynamics. when using wavefunction
> extrapolation and some other tricks (that are not yet in 3.11.)
> i get very good energy conservation with the attached input,
> which would bypass the problem of "tuning" the fictitious kinetic
> energy alltogether. when running those simulations side-by-side
> and fourier transforming the energy components one can also nicely
> see how the "drag" from the fictitious electron-dynamics and the
> deuteration of the "rim-hydrogens" affect the various vibrational
> modes.
I did the BO dynamics based partially on your settings (see attached
input file). The time step of 20 a.u. seems too big to me (see the red
plot on the attached ECLASSIC graph). The same run with 10 a.u. time
step (the black plot) looks much more stable, however it also exhibits a
drift of 6.3e-6 Ha/ps. Do you think one can accept this ?
I wonder what can be the origin of the suspicious drop in conserved
energy at the beginning of the 20 a.u. run ? After some 140 steps I
restarted the simulation for some reason or another with the attached
3restart.inp file.
Turning back to CP dynamics: my best result (VDB, emass=100 a.u., dt=2
a.u.) has a drift of 5.5e-5 Ha/ps in fictitious kinetic energy of the
electrons. This means that during 10 ps run the electronic subsystem
would gain 0.34 kcal/mol. Can it be assumed acceptable ? What do you
think of quenching the electrons every 10 ps in the case of longer
runs ?
Best regards,
Lukasz
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&CPMD
MOLECULAR DYNAMICS BO
RESTART WAVEFUNCTION COORDINATES LATEST
REAL SPACE WFN KEEP
CONVERGENCE ORBITALS
1.0e-6
EXTRAPOLATE WFN
4
TIMESTEP
20.0
TEMPERATURE
300.0
NOSE IONS MASSIVE
300.0 1800.0
MAXSTEP
20671
SUBTRACT COMVEL ROTVEL
10000
TRAJECTORY XYZ SAMPLE
-10
ISOLATED MOLECULE
CENTER MOLECULE
STORE
1000
&END
&SYSTEM
ANGSTROM
SYMMETRY
8
CELL ABSOLUTE
13.0 13.0 8.0 0.0 0.0 0.0
CUTOFF
35.0
&END
&DFT
FUNCTIONAL BLYP
GC-CUTOFF
5.D-6
&END
&ATOMS
*N_VDB_BLYP.psp FORMATTED
LMAX=P
4
1.480434744000 -1.261526338000 0.012486679000
-1.428836888000 -1.263268937000 0.020030520000
-1.482423266000 1.260607946000 0.012029901000
1.430161665000 1.261259358000 0.004480994000
*C_VDB_BLYP.psp FORMATTED
LMAX=P
20
2.764321879000 1.617573818000 -0.000125061000
3.855614684000 0.719804456000 -0.000057419000
3.883340408000 -0.678014026000 0.004378686000
2.816852951000 -1.603192445000 0.010125751000
2.919542448000 -3.046779447000 0.014515219000
1.637225743000 -3.547145051000 0.019451505000
0.739381956000 -2.412298909000 0.018118048000
-0.677939805000 -2.411241253000 0.021787063000
-1.565841060000 -3.552172948000 0.027767194000
-2.851571375000 -3.063067365000 0.029521295000
-2.763080194000 -1.618905630000 0.024634604000
-3.853925457000 -0.720052370000 0.024562307000
-3.883570717000 0.678208069000 0.020129751000
-2.818027537000 1.604764172000 0.014380689000
-2.917826697000 3.049092800000 0.009981340000
-1.634343765000 3.546387751000 0.005051935000
-0.738698022000 2.409860388000 0.006396510000
0.678687181000 2.408624576000 0.002727905000
1.566148163000 3.550017372000 -0.003252572000
2.852089024000 3.061544408000 -0.005009259000
*H_VDB_BLYP.psp FORMATTED
LMAX=S
14
4.829896620000 1.209449328000 -0.004160981000
4.874865030000 -1.131837359000 0.003273118000
3.847285348000 -3.609138791000 0.013924943000
1.339951403000 -4.589537686000 0.023583475000
-1.257219301000 -4.591087509000 0.030318008000
-3.775889801000 -3.630740840000 0.033747037000
-4.828126595000 -1.209793447000 0.028665970000
-4.875902354000 1.130204086000 0.021243303000
-3.843471723000 3.614955577000 0.010554882000
-1.334243713000 4.588096584000 0.000914849000
1.257025926000 4.588704910000 -0.005801358000
3.776400021000 3.629099090000 -0.009234599000
1.216317908000 -0.004972921000 0.009118666000
-1.218997172000 0.003787130000 0.015400566000
&END
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&CPMD
MOLECULAR DYNAMICS BO
RESTART WAVEFUNCTION COORDINATES VELOCITIES NOSEP ACCUMULATORS LATEST
REAL SPACE WFN KEEP
CONVERGENCE ORBITALS
1.0e-6
EXTRAPOLATE WFN
4
TIMESTEP
20.0
TEMPERATURE
300.0
NOSE IONS MASSIVE
300.0 1800.0
MAXSTEP
20671
SUBTRACT COMVEL ROTVEL
10000
TRAJECTORY XYZ SAMPLE
-10
ISOLATED MOLECULE
CENTER MOLECULE
STORE
1000
&END
&SYSTEM
ANGSTROM
SYMMETRY
8
CELL ABSOLUTE
13.0 13.0 8.0 0.0 0.0 0.0
CUTOFF
35.0
&END
&DFT
FUNCTIONAL BLYP
GC-CUTOFF
5.D-6
&END
&ATOMS
*N_VDB_BLYP.psp FORMATTED
LMAX=P
4
1.480434744000 -1.261526338000 0.012486679000
-1.428836888000 -1.263268937000 0.020030520000
-1.482423266000 1.260607946000 0.012029901000
1.430161665000 1.261259358000 0.004480994000
*C_VDB_BLYP.psp FORMATTED
LMAX=P
20
2.764321879000 1.617573818000 -0.000125061000
3.855614684000 0.719804456000 -0.000057419000
3.883340408000 -0.678014026000 0.004378686000
2.816852951000 -1.603192445000 0.010125751000
2.919542448000 -3.046779447000 0.014515219000
1.637225743000 -3.547145051000 0.019451505000
0.739381956000 -2.412298909000 0.018118048000
-0.677939805000 -2.411241253000 0.021787063000
-1.565841060000 -3.552172948000 0.027767194000
-2.851571375000 -3.063067365000 0.029521295000
-2.763080194000 -1.618905630000 0.024634604000
-3.853925457000 -0.720052370000 0.024562307000
-3.883570717000 0.678208069000 0.020129751000
-2.818027537000 1.604764172000 0.014380689000
-2.917826697000 3.049092800000 0.009981340000
-1.634343765000 3.546387751000 0.005051935000
-0.738698022000 2.409860388000 0.006396510000
0.678687181000 2.408624576000 0.002727905000
1.566148163000 3.550017372000 -0.003252572000
2.852089024000 3.061544408000 -0.005009259000
*H_VDB_BLYP.psp FORMATTED
LMAX=S
14
4.829896620000 1.209449328000 -0.004160981000
4.874865030000 -1.131837359000 0.003273118000
3.847285348000 -3.609138791000 0.013924943000
1.339951403000 -4.589537686000 0.023583475000
-1.257219301000 -4.591087509000 0.030318008000
-3.775889801000 -3.630740840000 0.033747037000
-4.828126595000 -1.209793447000 0.028665970000
-4.875902354000 1.130204086000 0.021243303000
-3.843471723000 3.614955577000 0.010554882000
-1.334243713000 4.588096584000 0.000914849000
1.257025926000 4.588704910000 -0.005801358000
3.776400021000 3.629099090000 -0.009234599000
1.216317908000 -0.004972921000 0.009118666000
-1.218997172000 0.003787130000 0.015400566000
&END
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