Hey Everyone,
I'm new to TOPAS so apologees if this question is simplistic. I'm working using TOPAS 6 and figured an easy way to generate an input file would be to input my structure in GUI mode, output the INP file, and then make the needed constraints to my structure. I'm attempting to refine data from a mayenite sample.
Here are the sites output from GUI without me making any changes beyond specifying fixed and refined parameters.
site Ca1 num_posns 0 occ Ca+2 @ 0.5 beq @ 1 x @ 0.9 y =0; : 0 z =0.75; : 0.75
site Ca2 num_posns 0 occ Ca+2 @ 0.5 beq @ 1 x @ 0.9 y =0; : 0 z =0.75; : 0.75
site Al1 num_posns 0 occ Al+3 @ 0.5 beq @ 1 x @ 0.02 y @ 0.2 z @ 0.125
site Al2 num_posns 0 occ Al+3 @ 0.5 beq @ 1 x =1; : 1 y =1/4; : 0.25 z =1/8; : 0.125
site O1 num_posns 0 occ O-2 =1; : 1 beq @ 1 x @ 0.9 y @ 0.8 z @ 0.7
site O2 num_posns 0 occ O-2 =1; : 1 beq @ 1 x @ 0.9 y @ 0 z @ 0
site O3 num_posns 0 occ O-2 @ 0.05 beq @ 1 x @ 0.75 y @ 0.125 z @ 0
And here's my attempt to name the parameters I want to refine and establish constraints. If its not clear I'm trying to constrain Al2 and O2 to have the same value for all three positions (X X X) and constrain the occupancy for the calcium and aluminum sites to add to 1 (Ca1+Ca2=1 and Al1+Al2=1).
site Ca1 num_posns 0 occ Ca+2 @ Ca1r beq @ 1 x @ 0.9 y =0; : 0 z =0.75; : 0.75
site Ca2 num_posns 0 occ Ca+2 = 1-Ca1r; beq @ 1 x @ 0.9 y =0; : 0 z =0.75; : 0.75
site Al1 num_posns 0 occ Al+3 @ Al1r beq @ 1 x @ Al1x y @ Al1x z @ Al1x
site Al2 num_posns 0 occ Al+3 = 1-Al1r; beq @ 1 x =1; : 1 y =1/4; : 0.25 z =1/8; : 0.125
site O1 num_posns 0 occ O-2 1 beq @ 1 x @ 0.9 y @ 0.8 z @ 0.7
site O2 num_posns 0 occ O-2 1 beq @ 1 x @ O2x y @ O2x z @ O2x
site O3 num_posns 0 occ O-2 @ 0.05 beq @ 1 x @ 0.75 y @ 0.125 z @ 0
Where am I going wrong here?