Format of datafiles
LAMDA | Atomic datafiles | Molecular datafiles | RADEX

Below follows a description of the format adopted for presenting the atomic and molecular data in LAMDA. Any similarities with datafiles from other authors is completely coincidental.

% Lines 1-2: molecule (or atom) name
% Lines 3-4: molecular (or atomic) weight (a.m.u.)
% Lines 5-6: number of energy levels (NLEV)
% Lines 7-7+NLEV: level number, level energy (cm-1), statistical weight. These numbers may be followed by additional info such as the quantum numbers, which are however not used by the program. The levels must be listed in order of increasing energy.
% Lines 8+NLEV-9+NLEV: number of radiative transitions (NLIN)
% Lines 10+NLEV-10+NLEV+NLIN: transition number, upper level, lower level, spontaneous decay rate (s-1). These numbers may be followed by additional info such as the line frequency, which is however not used by the program.
% Lines 11+NLEV+NLIN-12+NLEV+NLIN: number of collision partners
% Lines 13+NLEV+NLIN-14+NLEV+NLIN: collision partner ID and reference. Valid identifications are: 1=H2, 2=para-H2, 3=ortho-H2, 4=electrons, 5=H, 6=He.
% Lines 15+NLEV+NLIN-16+NLEV+NLIN: number of transitions for which collisional data exist (NCOL)
% Lines 17+NLEV+NLIN-18+NLEV+NLIN: number of temperatures for which collisional data exist
% Lines 19+NLEV+NLIN-20+NLEV+NLIN: values of temperatures for which collisional data exist
% Lines 21+NLEV+NLIN-21+NLEV+NLIN+NCOL: transition number, upper level, lower level; rate coefficients (cm3s-1) at each temperature. The program interpolates between rate coefficients in the specified temperature range. Outside this range, it assumes the collisional de-excitation rate coefficients are constant with T, i.e., it uses rate coefficients specified at the highest T (400 K in this case)also for higher temperatures, and similarly at temperatures below the lowest value (10 K in this case) for which rate coefficients were specified.

Example molecular data file: HCO+

!MOLECULE HCO+
!MOLECULAR WEIGHT
29.0
!NUMBER OF ENERGY LEVELS
21
!LEVEL + ENERGIES(cm-1) + WEIGHT + J
1 0.000000000 1.0 0
2 2.975008479 3.0 1
(etc)
21 624.269300464 41.0 20
!NUMBER OF RADIATIVE TRANSITIONS
20
!TRANS + UP + LOW + EINSTEINA(s-1) + FREQ(GHz)
1 2 1 4.251e-05 89.18839570
2 3 2 4.081e-04 178.37481404
(etc)
20 21 20 4.955e-01 1781.13802857
!NUMBER OF COLL PARTNERS
1
!COLLISIONS BETWEEN
1 H2-HCO+ from Flower (1999)
!NUMBER OF COLL TRANS
210
!NUMBER OF COLL TEMPS
12
!COLL TEMPS
10.0 20.0 30.0 50.0 70.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0
!TRANS + UP + LOW + COLLRATES(cm3 s-1)
1 2 1 2.6e-10 2.3e-10 2.1e-10 2.0e-10 1.9e-10 1.8e-10 2.0e-10 2.2e-10 2.3e-10 2.5e-10 2.7e-10 2.8e-10
2 3 1 1.4e-10 1.2e-10 1.1e-10 1.0e-10 9.2e-11 8.8e-11 8.4e-11 8.2e-11 8.1e-11 8.3e-11 8.1e-11 8.5e-11
(etc)
210 21 20 3.7e-10 3.6e-10 3.6e-10 3.5e-10 3.5e-10 3.5e-10 3.8e-10 4.0e-10 4.4e-10 4.7e-10 5.0e-10 5.2e-10


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