Dear Users,

Recently, I started using ALPS for Classical Monte Carlo with Python interface. I would like to do calculations for square-lattice with 1st (vertical), 2nd (horizantal) and 3rd (diagonal) nearest neighbours interactions J0, J1, J2. For the I have created a square-lattice.xml for 4x4 lattice.

If I run the code in jupyter notebook, i am getting following error:

parsing task files ... could not find graph/lattice specified in parameters: name was: 'Square_lattice'

Please help me to find the error (I mean the xmal file written properly?), Do I need to do before I have to use my own xml file?

My code is as follows: -------------------------------------------------------------------------------------------------------------------------------------------------------------------- import pyalps import matplotlib.pyplot as plt import pyalps.plot

parms = [] for l in [16]: for t in [1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15]: parms.append( { 'LATTICE_LIBRARY' : "./Square-lattice.xml", 'LATTICE' : "Square_lattice", 'T' : t, 'S' : 2.62, 'J0' : 0.52 , 'J1' : -0.09 , 'J2' : 0.86 , 'THERMALIZATION' : 1000, 'SWEEPS' : 400000, 'UPDATE' : "local", 'MODEL' : "Ising", 'L' : l } )

input_file = pyalps.writeInputFiles('Square_isg',parms) pyalps.runApplication('spinmc',input_file,Tmin=10) pyalps.evaluateSpinMC(pyalps.getResultFiles(prefix='Square_isg')) data = pyalps.loadMeasurements(pyalps.getResultFiles(prefix='Square_isg'),['|Magnetization|', 'Specific Heat']) magnetization_abs = pyalps.collectXY(data,x='T',y='|Magnetization|',foreach=['L']) spec_heat = pyalps.collectXY(data,x='T',y='Specific Heat',foreach=['L'])

#make plots plt.figure() pyalps.plot.plot(magnetization_abs) plt.xlabel('Temperature $T$') plt.ylabel('Magnetization $|m|$') plt.legend() plt.title('2D Ising model')

plt.figure() pyalps.plot.plot(spec_heat) plt.xlabel('Temperature $T$') plt.ylabel('Specific Heat $c_v$') plt.legend() plt.title('2D Ising model') plt.show() ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ my xml file is below: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ <LATTICES>

<LATTICE name="Square_lattice" dimension="2"> <PARAMETER name="a" default="1"/> <PARAMETER name="b" default="1"/> <BASIS> <VECTOR>a 0</VECTOR> <VECTOR>0 b</VECTOR> </BASIS> <RECIPROCALBASIS> <VECTOR>2*pi/a 0</VECTOR> <VECTOR>0 2*pi/b</VECTOR> </RECIPROCALBASIS> </LATTICE>

<UNITCELL name="simple2d" dimension="2" vertices = "4"> <VERTEX><COORDINATE> 0.0 0.0</COORDINATE></VERTEX> <VERTEX><COORDINATE> 0.5 0.0</COORDINATE></VERTEX> <VERTEX><COORDINATE> 0.0 0.5</COORDINATE></VERTEX> <VERTEX><COORDINATE> 0.5 0.5</COORDINATE></VERTEX>

<EDGE type="0"><SOURCE vertex="1" offset="0 0"/><TARGET vertex="2" offset="0.5 0"/></EDGE> <EDGE type="1"><SOURCE vertex="1" offset="0 0"/><TARGET vertex="3" offset="0 0.5"/></EDGE> <EDGE type="2"><SOURCE vertex="1" offset="0 0"/><TARGET vertex="4" offset="0.5 0.5"/></EDGE> </UNITCELL>

<LATTICEGRAPH name = "Square_lattice 4x4" > <FINITELATTICE> <LATTICE ref="Square_lattice"/> <EXTENT dimension="1" size="4"/> <EXTENT dimension="2" size="4"/> <BOUNDARY type="periodic"/> </FINITELATTICE> <UNITCELL ref="simple2d"/> </LATTICEGRAPH>

</LATTICES> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Thank you in advance Dr. Bheema Lingam Chittari Post Doctoral Researcher, Room No:14-115, Department of Physics, University of Seoul, 163 Seoulsiripdae-ro, Dongdumen-gu, Seoul, South Korea