Why does Thermo-Calc one axis equilibrium calculation get stuck in never ending loop? [closed]

I've been trying to run a Thermo-Calc one axis equilibrium calculation on some quaternary alloys in the TCHEA4 database. Most of the calculations work fine, but for some alloys it gets stuck in a loop (forever) where it is trying to find the start of a phase change. I can sometimes get it to run for these problematic alloys by setting the global test interval to 1 or by increasing the number of grid points for global minimization, but I don't want to have to fudge things like that. What is the reason the calculations are hanging and how can it be fixed reliably?

:
Phase Region from    651.989
11:35:58,357 INFO   BCC_B2#1 SIGMA#1 SIGMA#2
11:35:58,478 INFO   Global test at  5.80000E+02
11:35:59,482 INFO    Backtracking to find phase change for SIGMA#3
11:35:59,617 INFO   Global check of adding phase at  6.51989E+02
11:36:01,482 INFO   Calculated     4 equilibria
11:36:01,483 INFO   Phase Region from    651.989
11:36:01,484 INFO   BCC_B2#1 SIGMA#1 SIGMA#2 SIGMA#3
11:36:01,557 INFO   Global check of removing phase at  6.51989E+02
11:36:03,571 INFO   Calculated     3 equilibria
11:36:03,572 INFO   Phase Region from    651.989
11:36:03,572 INFO   BCC_B2#1 SIGMA#1 SIGMA#2
11:36:03,710 INFO   Global test at  5.80000E+02
11:36:05,276 INFO    Backtracking to find phase change for SIGMA#3
11:36:05,477 INFO   Global check of adding phase at  6.51989E+02
11:36:07,188 INFO   Calculated     4 equilibria
11:36:07,189 INFO   Phase Region from    651.989
11:36:07,189 INFO   BCC_B2#1 SIGMA#1 SIGMA#2 SIGMA#3
11:36:07,275 INFO   Global check of removing phase at  6.51989E+02
11:36:07,675 INFO   Calculated     3 equilibria
11:36:07,675 INFO   Phase Region from    651.989
11:36:07,676 INFO   BCC_B2#1 SIGMA#1 SIGMA#2
11:36:07,800 INFO   Global test at  5.80000E+02
11:36:09,098 INFO    Backtracking to find phase change for SIGMA#3
11:36:09,318 INFO   Global check of adding phase at  6.51989E+02
11:36:11,029 INFO   Calculated     4 equilibria
11:36:11,030 INFO   Phase Region from    651.989
11:36:11,031 INFO   BCC_B2#1 SIGMA#1 SIGMA#2 SIGMA#3
11:36:11,096 INFO   Global check of removing phase at  6.51989E+02
11:36:13,019 INFO   Calculated     3 equilibria
11:36:13,020 INFO   Phase Region from    651.989
11:36:13,021 INFO   BCC_B2#1 SIGMA#1 SIGMA#2


This just continues without end.

• +1 but please copy and paste the output rather than showing a screenshot. Use the "code" block for the output to look nice. – Nike Dattani Nov 19 '20 at 17:58
• Did your compute-equilibrium (c-e) command (in console mode) proceed without any error (after defining the systems and conditions) ? Usually, in case of quaternary systems, the number of participating phases are high and you get an error after c-e command. In that case, you need to reject some phases and repeat the calculation. – Niraja moharana Nov 28 '20 at 13:35
• I agree with @NikeDattani that it would be helpful if you could share the code block, or at least the command used. Also, rejecting some phases may help but if the problem persists then you can go the old way by using the original approach of combining change-status and set-condition commands and see if it works. – Achintya Patra Nov 29 '20 at 14:53
• I did it in the GUI (I usually use TC-Python and sometimes the GUI). I can share some screen shots of the setup though, if that would be helpful – sgp45 Nov 30 '20 at 15:05
• @sgp45 Please share the screenshots. People need to be able to see what you did to try to reproduce the problem or understand why you got unexpected results. – Nike Dattani Feb 28 at 19:46