Dear all, I was trying to specify the number of eigenvalues calculated by sparsediag, using NUMBER_EIGENVALUES=1 as described here: http://alps.comp-phys.org/mediawiki/index.php/Documentation:sparsediag However, sparsediag nevertheless calculates the lowest eigenvalue for each wavevector. Does this option no longer work? The problem persists even for a simple test case: LATTICE="chain lattice" MODEL="spin" local_S=0.5 Jxy=0.0 Jz="-1.0" Gamma=0.5 NUMBER_EIGENVALUES=1 MEASURE_CORRELATIONS[Diagonal spin correlations]=Sz MEASURE_CORRELATIONS[Offdiagonal spin correlations]="Splus:Sminus" {L=20;} A second question pertains to the output of sparsediag. With the above input file, the results contain the line <PARAMETER name="TOTAL_MOMENTUM">5.7595865315812870833</PARAMETER> However, I have not specified TOTAL_MOMENTUM... Any help is appreciated. Best regards, Martin Hohenadler -- ==================================================== Dr Martin Hohenadler ---------------------------------------------------- Institute for Theoretical Physics and Astrophysics University of Würzburg Am Hubland, 97074 Würzburg ---------------------------------------------------- Tel: +49 (0)151 53506248 (mobile) ---------------------------------------------------- email: martin.hohenadler@physik.uni-wuerzburg.de web : www.hohenadler.com ====================================================