[Pw_forum] spin polarization of a organo-metallic compound

[Alex Granov]

Hi
We are studying an organo-metallic compound which contains 3 Benzene rings, phosphorous, oxygen, Iodine, and rhenium atoms.Our quantum chemistry study using B3LYP/6-31+G* (Gaussian basis set) shows that the ground state of the system is singlet (spin -unpolarized). We attempted to optimize this structure using quantum espresso to calculate some other electronic properties. Then surprisingly we found that the spin-polarized system is more stable than the spin-unpolarized one in contrast with our quantum chemistry study. In the following you can see my input file and I wonder whether there is something wrong in the input that made the very noticeable contrast. I appreciate your comments to understand the issue and solve it in advance. 
q/e input:&control    calculation='relax',    restart_mode='from_scratch',    prefix='Re-Be',    pseudo_dir = './pseudo/',    outdir='./tmp/',    tprnfor=.t. ,    etot_conv_thr=1.0D-4,    forc_conv_thr=1.0D-3,    nstep=300,    dt=10,     / &system    ibrav= 8, a=20, b=20, c=20,  nat=37, ntyp=6,    ecutwfc = 30, ecutrho = 300, occupations='smearing', smearing='marzari-vanderbilt', degauss=0.005,    nspin=2 , starting_magnetization(1)=1 ,starting_magnetization(2)=1 ,  starting_magnetization(3)=1 , starting_magnetization(4)=1 , starting_magnetization(5)=1 , starting_magnetization(6)=1 , / &electrons    conv_thr = 1.0d-6,    mixing_beta=0.2,    mixing_mode=local-TF, / &IONS  ion_dynamics="bfgs",  upscale=100.0D0 ,/ATOMIC_SPECIESRe 186.207  Re.pbe-hgh.UPFO  15.999   O.pbe-rrkjus.UPFC 12.000    C.pbe-rrkjus.UPFH 1.000     H.pbe-rrkjus.UPFI 126.90   I.pbe-n-rrkjus_psl.0.2.UPFP  30.9737  P.pbe-n-van.UPFK_POINTS {gamma}    

-------------------------------------------------Alex GranovМосковский физико-технический институт (MIPT)Moscow, Russia 		 	   		  
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