Dear Dr. Dubbeldum
Thanks a lot for your response. I compared my results with experimental data. The results for liquid density are accurate at all temperatures with the error of 1%, but the results for vapor density are not accurate with the error of 20%. When I compared my results with the results of a paper ,published in 1998, I understood that they could not get the accurate results for vapor density using TraPPE-UA.
What is the reason that vapor density is not achieved? Is not it because of the length of boxes?
SimulationType MonteCarlo
NumberOfCycles 100000
NumberOfInitializationCycles 10000
RestartFile no
ContinueAfterCrash no
WriteBinaryRestartFileEvery 1000
PrintEvery 1000
PrintPropertiesEvery 1000
ChargeMethod Ewald
EwaldPrecision 1e-5
Forcefield TraPPE-UA
CutOffVDW 14
CutOffChargeCharge 14
Box 0
BoxLengths 30 30 30
BoxAngles 90 90 90
ExternalTemperature 200
Movies yes
WriteMoviesEvery 1000
ComputeEnergyHistogram yes
ComputeNumberOfMoleculesHistogram yes
ComputeMolecularPressure yes
Box 1
BoxLengths 30 30 30
BoxAngles 90 90 90
ExternalTemperature 200
Movies yes
WriteMoviesEvery 1000
ComputeEnergyHistogram yes
ComputeNumberOfMoleculesHistogram yes
ComputeMolecularPressure yes
GibbsVolumeChangeProbability 0.05
Component 0 MoleculeName propane
MoleculeDefinition TraPPE-UA
TranslationProbability 0.5
RotationProbability 0.5
ReinsertionProbability 0.5
GibbsSwapProbability 0.5
CreateNumberOfMolecules 100 100