Structure of the ffield.reax.* files

Dear lammps community,

I have a small doubt about the structure of the ffield.reax.* files to define the parameters for the Reax Potential in lammps. In the text files where the parameters are defined there are comments intended to describe the order of the parameters in the line. However in some of the lists of parameters the amount of descriptors in the commented line are smaller that the amount of numbers listed. For instance this fragment from the ffield.reax.rdx:

10 ! Nr of bonds; Edis1;LPpen;n.u.;pbe1;pbo5;13corr;pbo6
pbe2;pbo3;pbo4;Etrip;pbo1;pbo2;ovcorr
1 1 141.9346 113.4487 67.6027 0.1554 -0.3045 1.0000 30.4515 0.4283
0.0801 -0.2113 8.5395 1.0000 -0.0933 6.6967 1.0000 0.0000
1 2 163.6889 0.0000 0.0000 -0.4525 0.0000 1.0000 6.0000 0.5921
12.1053 1.0000 0.0000 1.0000 -0.0097 8.6351 0.0000 0.0000

It indicates that 10 sets of parameters for bond interactions are going to be defined. The parameters descriptors are:

(1)Edis1; (2)LPpen; (3)n.u.; (4)pbe1; (5)pbo5; (6)13corr; (7)pbo6; (8)pbe2; (9)pbo3; (10)pbo4; (11)Etrip; (12)pbo1; (13)pbo2; (14)ovcorr.

A total of 14 parameters; but the listed numbers are 16 (the first two numbers just indicate which interactions is being defined):

1 1 (1)141.9346 (2)113.4487 (3)67.6027 (4)0.1554 (5)-0.3045 (6)1.0000 (7)30.4515 (8)0.4283 (9)0.0801 (10)-0.2113 (11)8.5395 (12)1.0000 (13)-0.0933 (14)6.6967 (15)1.0000 (16)0.0000

I am interested in knowing how lammps reads this file, and which code is used for that. I hope that by reading the code I could get a better understanding of the order in which the parameters for the ReaxFF are written in the ffiled.reax.* files. Could you share with me some information about the structure of the ffiled.reax.* files? or point me toward the code which read them? I would be very thankful for your help.

Best regards, and thanks for your time.

The description in the fffield.reax files are not entirely accurate. These files are read in from reaxc_ffield.cpp, and the particular section you are interested in starts on line 307.

By comparing the source code and the force field file, you can find that 14 out of the 16 parameters are used.

Ray