[CPMD-list] Bohr length unit

[Martin Konopka]

Dear CPMD develpers,

The Bohr length unit expressed in Angtroms is written several times
inside the code (3.11.1). What is worse there are two slightly different
values:
0.529177d0 and 0.529177249D0
See grep below:

[konopka at ccms12 SOURCE] grep "0.529177" *.F
g_loc_dr.F:          FAC = TPIBA / 0.529177d0
g_loc_exp_ide.F:        FAC = TPIBA / 0.529177d0
g_loc_exp_sum.F:      FAC = TPIBA / 0.529177d0
g_loc_exp_sum.F:      FAC = TPIBA / 0.529177d0
g_loc_spread_ide.F:        FAC = TPIBA / 0.529177d0
g_loc_spread_sum.F:      FAC = TPIBA / 0.529177d0
g_loc_util.F:        FAC = 1.D0 / 0.529177d0
secder.F:      b=0.529177249d0
setcnst.F:      FBOHR=1.D0/0.529177249D0

Sometime one needs to recalculate coordinates or cell vectors from AU to
Angstroms or vice versa. Using slightly different values of the Bohr unit
introduces small but annoying differences into quantities.

Could in future CPMD releases be only one value of the Bohr unit?
(And in one file only, if possible.)
And perhaps set to most accurate value currently known.
There may be similar problem with other constants too, I did not check...

Thanks.

Greetings
Martin Konopka.



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Dr. Martin Konopka             http://www.ccms.elf.stuba.sk/konopka.html
Department of Physics, CCMS                      tel: +421 (0)2 60291714
Slovak University of Technology (FEI STU)        fax: +421 (0)2 65411483
Ilkovicova 3, 812 19 Bratislava, Slovakia
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