[QE-users] Can an increase in the basis-set increase the total energy of a system?

[NM SALMA]

Hello,

I was doing the convergence testing of CuI material.
For a fixed Ecutwfc value, when I increase the Ecutrho the total energy of the system increase. I was expecting the inverse.
For example for Ecutwfc=90 Ry and Ecutrho= 180 Ry the total energy= -2368.11704109 Ry
and for Ecutwfc=90 Ry and Ecutrho=450 Ry the total energy= -2368.11613851 Ry.
Is that logic? I thought that an increase in the basis-set minimize the system energy.

I also remarked in the pseudopotential file  that :
  For Cu : - Suggested minimum cutoff for wavefunctions:  45. Ry
                - Suggested minimum cutoff for charge density: 236. Ry

  For I  :     - Suggested minimum cutoff for wavefunctions:  24. Ry
                 - Suggested minimum cutoff for charge density: 109. Ry

So how it can be that the suggested minimum cutoff for charge density of Cu is 236 Ry, while I found that the system have a minimum total energy for Ecutrho=180 Ry
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