Electronic structure and charge distribution topology of MgH2 doped with 3d transition metals

• Published in: International journal of hydrogen energy Vol. 39; no. 11; pp. 5874 - 5887
• Main Authors: MAMULA, Bojana Paskaš, NOVAKOVIC, Jasmina Grbović, RADISAULJEVIC, Ivana, IVANOVIC, Nenad, NOVAKOVIC, Nikola
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 04.04.2014; Elsevier
• Subjects: Ab initio calculations; Alternative fuels. Production and utilization; Applied sciences; Bader's charge analysis; Energy; Exact sciences and technology; Fuels; Hydrogen; Hydrogen storage; MgH2; Transition metals; MgH2; Transition metals; Hydrogen storage; Ab initio calculations; Bader's charge analysis; Electronic structure; Hydrogen; Transition metal; MgH
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2014.01.172

Ab initio electronic structure calculations of the Mg15TMH32 (TM – transition metals – 6.25 at.%) systems for the entire 3d TM series have been performed using full-potential (linearized) augmented plane waves with addition of local orbitals (FP-LAPW + LO and APW + lo) as implemented in WIEN2k code and projected augmented waves (PAW) method using Abinit code. Details of bonding and mechanism of the TM impurities influence on destabilization of MgH2 were established by investigation of changes of electronic structure after the TM impurities insertion into MgH2 and by using the “atoms in molecules” (AIM) Bader's charge density topology analysis. The obtained trends of all calculated observables show that along the 3d series TMs accomplish different kinds of bonding with nearest and next-nearest neighbor hydrogen atoms that in general weaken related Mg–H bonds and destabilize the surrounding MgH2 matrix. •Bader charge analysis provides picture of different TM–H bonding mechanisms within MgH2 matrix.•Second neighbor H–H bond in MgH2 is absent in first coordination of the TMs impurities.•Observed trends of calculated physical quantities explained with change of the TM–H bond nature.•Stronger coupling with surrounding H atoms followed by bond weakening in several shells around TM.