SCF Fails to start for MoO3

exciting
1

Hello,
Having trouble to get an SCF (and eventual GeoOpt) to start for MoO3.
the calculation seems to stall at the begining of the SCF, even with 28 cores and exciting_purempi.

I pulled a cif file of MoO3 off of materials project

and wrote an input.xml file with ase’s exciting writer.

I found that the calculation does not start, and instead hands on the begining of the SCF calculation.

Naively, it seems that muffin tin radii sum for O+Mo is greater than the distance between atoms, so i set the Mo radius to be 1.9 and the O radius to be 1.2 using a kpt sampling of [8,8,8]

Is there something i am missing?

Here is the input.xml


<?xml version="1.0" ?>
<input xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://xml.exciting-code.org/excitinginput.xsd">
	<title>MoO3 Geo Opt</title>
	<structure speciespath="exciting/exciting/species" autormt="false" tshift="true">
		<crystal>
			<basevect>6.95667380701739 0.00000000000000 0.00000000000000</basevect>
			<basevect>0.00000000000000 7.40534651109514 0.00000000000000</basevect>
			<basevect>0.00000000000000 0.00000000000000 26.88905760858228</basevect>
		</crystal>
		<species speciesfile="Mo.xml" chemicalSymbol="Mo" rmt = "1.9">
			<atom coord="0.25000000000000 0.42300961000000 0.60205717000000"/>
			<atom coord="0.75000000000000 0.57699039000000 0.39794283000000"/>
			<atom coord="0.75000000000000 0.92300961000000 0.89794283000000"/>
			<atom coord="0.25000000000000 0.07699039000000 0.10205717000000"/>
		</species>
		<species speciesfile="O.xml" chemicalSymbol="O" rmt = "1.2">
			<atom coord="0.25000000000000 0.46632673000000 0.71834359000000"/>
			<atom coord="0.75000000000000 0.53367327000000 0.28165641000000"/>
			<atom coord="0.75000000000000 0.96632673000000 0.78165641000000"/>
			<atom coord="0.25000000000000 0.03367327000000 0.21834359000000"/>
			<atom coord="0.25000000000000 0.49853619000000 0.43558467000000"/>
			<atom coord="0.75000000000000 0.50146381000000 0.56441533000000"/>
			<atom coord="0.75000000000000 0.99853619000000 0.06441533000000"/>
			<atom coord="0.25000000000000 0.00146381000000 0.93558467000000"/>
			<atom coord="0.25000000000000 0.98268220000000 0.58709074000000"/>
			<atom coord="0.75000000000000 0.48268220000000 0.91290926000000"/>
			<atom coord="0.75000000000000 0.01731780000000 0.41290926000000"/>
			<atom coord="0.25000000000000 0.51731780000000 0.08709074000000"/>
		</species>
	</structure>
	<groundstate outputlevel="normal"
                 xctype="GGA_PBE_SOL" 
                 ngridk="8 8 4" 
                 gmaxvr="15.0" />
</input>
2

Hi strategos,

Some general points:

  • Don’t use exciting_purempi, you won’t have any threading support (it’s for development purposes only). Use smp_and_mpi.

  • W.r.t the input file, the lattice vectors look like Bohr and atomic positions look fractional, which is correct

  • If the muffin tin radii are nearly touching, you’ll still have problems with the basis. Try a RMT_O + RMT_Mo = 0.8 * bond length and go from there.

  • rgkmax should really be specified, this will affect the basis quality (but can be low for testing)

Can you give the INFO.OUT and any errors warnings?

Cheers,
Alex

3

Hi,

Ok i will recompile for exciting_mpiandsmp.

I did try a smaller rmt for Mo and O and found that yes, rgkmax was the problem.

I think that solved the error.