/usr/share/xcrysden/util/unitconv is in xcrysden-data 1.5.53-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 | #!/bin/sh
# \
# this line restarts tclsh \
exec tclsh $0 "$@"
#
# Usage: unitconv unit value
# or: unitconv unit expr
#
#
# supported units
set energy_units {
au
ry
ev
kjm
kcalm
kj
kcal
erg
}
set length_units {
angs
bohr
m
}
set allowed_units "$energy_units $length_units"
# check for correctness of specified unit on command-line
set unit [string tolower [lindex $argv 0]]
if { [lsearch -nocase $allowed_units $unit] < 0 } {
puts stderr "input unit not known; must be one of [join $allowed_units {, }]"
exit
}
# ------------------------------------------------------------------------
# PHYSICAL CONSTANTS
#
# Physical constants, SI (NIST CODATA 2006), Web Version 5.1
# http://physics.nist.gov/constants
set j 1.000000000000
set au 4.35974394e-18; # J
set ev 1.602176487e-19; # J
set mol 6.02214129e23
# thermo-kilocalorie (International Standard ISO 31-4: Quantities and
# units – Part 4: Heat. Annex B (informative): Other units given for
# information, especially regarding the conversion
# factor. International Organization for Standardization, 1992.)
set kcal 4184; # J
# from wikipedia:
set erg 1e-7; # J
#--------------------------------
# Energy Units (use J as default)
#--------------------------------
set kj 1000.00000000000000
set ry [expr $au / 2.0]
set kjm [expr $kj / $mol]
set kcalm [expr $kcal / $mol]
#-----------------------------------------
# Distance Units (use Angstrom as default)
#-----------------------------------------
set angs 1.0
set bohr 0.52917720859
set m 1.e10
# ------------------------------------------------------------------------
#
# evaluate & convert user specified expression/value
#
upvar #0 $unit un_fac
# parse the command line arguments
foreach item [lrange $argv 1 end] {
append numbers [format "%s " $item]
}
set orig_value [expr 1.0 * ($numbers)];
# store result either in J or Angstroms !!!
set value [expr $un_fac * $orig_value];
#
# PRINTOUT
#
puts stdout "$orig_value $unit = "
if { [lsearch -nocase $energy_units $unit] > -1 } {
# do we have energy ?
foreach _un $energy_units {
upvar #0 $_un unval
set val [expr $value / $unval]
puts stdout " = $val $_un"
}
} elseif { [lsearch -nocase $length_units $unit] > -1 } {
# ... or length ?
foreach _un $length_units {
upvar #0 $_un unval
set val [expr $value / $unval]
puts stdout " = $val $_un"
}
}
exit 0
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