[gmx-users] 转发：entropy calculation by g_anaeig

[sunyeping]

Yeping Sun
Institute of Microbiology, Chinese Academy of Sciences
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发件人：孙业平 <sunyeping at aliyun.com>
发送时间：2014年8月30日(星期六) 23:19
收件人：vmd-l <vmd-l at ks.uiuc.edu>
主　题：entropy calculation by g_anaeig

Dear all,

I am using g_anaeig to calculate entropy from the MD trajectory. Firstly I got eigenvec.trr by g_covar command, and then used the following command:

g_anaeig -s md_0_1.tpr -v eigenvec.trr -b 0 -e 225 -n index.ind -entropy

However, I didn't got the entropy values. The output was:
.......... ............eigval[1090] = -1.44331
eigval[1093] = -1.35067
eigval[1096] = -1.02231
eigval[1099] = -0.962267
eigval[1102] = -1.02198
eigval[1105] = -0.775765
eigval[1108] = -0.51662
eigval[1111] = -0.542334
eigval[1114] = -0.431655
eigval[1117] = -0.163827
eigval[1120] = -0.00552675
The Entropy due to the Quasi Harmonic approximation is inf J/mol K
The Entropy due to the Schlitter formula is nan J/mol K
Reading file md_0_1.tpr, VERSION 5.0-dev (single precision)
Reading file md_0_1.tpr, VERSION 5.0-dev (single precision)
1 eigenvectors selected for output: 1


Could you tell why why the entropy cannot be calculate properly? 

Best regards.
.

Yeping