Did you set Q2 and Q3? or A1z and A1xy? Also, you could just use the "spin" model for this and set Jxy0, Jz0, Jxy1 and Jz1

Matthias

On Nov 17, 2009, at 7:32 PM, Fu-Jiun Jiang ITP wrote:

Dear all

If I want to study bilayer Heisenberg model, what's wrong with the following Hamiltonian (the error message read " bad lexical cast: source type value could not be interpreted as target ")? Many thanks in advance.

<PARAMETER name="Az" default="Q"/> <PARAMETER name="Axy" default="Az"/> <PARAMETER name="Q" default="1"/> <PARAMETER name="A1z" default="Q2"/> <PARAMETER name="A1xy" default="Q3"/> <PARAMETER name="h" default="h1"/> <BASIS ref="spin"/> <SITETERM site="i"> -h1*Sz(i) </SITETERM> <BONDTERM type="1" source="i" target="j"> Az*Sz(i)*Sz(j)+Axy*exchange_xy(i,j) </BONDTERM> <BONDTERM type="0" source="i" target="j"> A1z*Sz(i)*Sz(j)+A1z*A1xy*exchange_xy(i,j) </BONDTERM>

Sincerely, Fu-Jiun