From: Shyno Mathew (
Date: Mon Dec 02 2013 - 11:42:37 CST

Dear all,
I am trying to use the parseFEP plugin of VMD version 1.9. FEP calculations
were done using namd 2.8
The temperature is set to 300 K, the BAR estimator and disp options are
turned on. For Gram-Charlier oder, I put 0.
I am getting the following errors:
domain error: argument not in valid range
domain error: argument not in valid range
    while executing
"expr sqrt($instant_error_gauss) "
    (procedure "::ParseFEP::FEP_formula" line 361)
    invoked from within
"::ParseFEP::FEP_formula $file $file_entropy $file_lambda $window
$mean_xi $fororback"
    (procedure "::ParseFEP::normal_parse_log" line 60)
    invoked from within
"::ParseFEP::normal_parse_log $::ParseFEP::fepofile forward "
    (procedure "::ParseFEP::namdparse" line 172)
    invoked from within
    (in namespace inscope "::ParseFEP" script line 21)
    invoked from within
"::namespace inscope ::ParseFEP {
    ##if {$::ParseFEP::fepbofile != ""} {set ::ParseFEP::sosindex 1 }

    if { [string length $fepofile] < 1 } {
    invoked from within
".parseFEP.runbutton invoke"
    ("uplevel" body line 1)
    invoked from within
"uplevel #0 [list $w invoke]"
    (procedure "tk::ButtonUp" line 22)
    invoked from within
"tk::ButtonUp .parseFEP.runbutton"
    (command bound to event)


Shyno Mathew
PhD student
Department of Chemical Engineering
Columbia University