Previously, I used DMRG to calculate the model containing the external potential, but now I would like to try to use MPS to calculate it.When i use MPS, I meet a question of potential.
My potential setting like this
<SITETERM site="i">
<PARAMETER name="mu#" default="mu"/>
<PARAMETER name="U#" default="U"/>
<PARAMETER name="Vout" default="0"/>
-mu#*n(i)+U#*n_up(i)*n_down(i)+Vout*((x-(L-1)/2.0)^2)*n(i)
</SITETERM>
I use the model ,lattice and command like I used in DMRG, but the computer prompt like :
Exception thrown:
Cannot evaluate x
By using DMRG, it can be calculated correctly, but MPS will prompt the error, i wonder what should I do to correct it?
It is highly grateful for your any suggestion.
Yours sincerely,
Xingbo Wei
Zhejiang Normal University
Jinhua,230014,
China