Dear everyone,

I am trying to set up an ICONST file for a calculation in which I want to perform a slow-growth approach for NOH formation via the Eley-Rideal (ER) mechanism:

*NO + H₂O + e⁻ → *NOH + OH⁻

My collective variable is defined as CV = d₁ - d₂, where d₁ is the distance between the oxygen and hydrogen of a water molecule, and d₂ is the distance between the oxygen of NO and the hydrogen from water. I set CV = 0.0001 as the initial value.

I want to model the process in which water donates a proton to NO to form NOH and to calculate the free energy profile.

I set the ICONST file as follows:

R 1 (index of H) 2 (index of O in water) 0

R 1 (index of H) 3 (index of O in NO₃) 0

S 1 -1 8

I also prepared the POTCAR, KPOINTS, POSCAR, and INCAR files according to the VASP tutorial for slow-growth calculations.

However, when I ran the job, I received the following error:

Error reading ICONST (item 1): unsupported coordinate type

I would like to ask whether my ICONST file is correct or not. Because I found the other inputs are fine until now.

Thank you so much.

Best regards,