ELECTRONIC STRUCTURE AND CHEMICAL BONDING IN ALKALINE EARTH METAL SUBNITRIDES: PHOTOEMISSION STUDIES AND BAND STRUCTURE CALCULATIONS

1998 ◽  
Vol 59 (9) ◽  
pp. 1527-1536 ◽  
Author(s):  
U. Steinbrenner ◽  
P. Adler ◽  
W. Hölle ◽  
A. Simon
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Chemical Bonding ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Band Structure Calculations ◽  
Structure Calculations

scholarly journals Mixed Alkaline Earth Germanides A2MGe2(A= Ca/Sr; M= Sn,Pb)

2014 ◽  
Vol 70 (a1) ◽  
pp. C1701-C1701
Author(s):  
Michael Jehle ◽  
Michael Langenmaier ◽  
Julia Steckhan ◽  
Caroline Röhr
Keyword(s):  
Band Structure ◽  
Chemical Bonding ◽  
Alkaline Earth ◽  
Radius Ratio ◽  
Zigzag Chain ◽  
Band Structure Calculations ◽  
Square Planar ◽  
New Type ◽  
Bottom Left ◽  
Structure Calculations

The crystal structures of the mixed alkaline earth tetrelides with the composition (CaxSr1-x)2MGe2 (M= Sn,Pb) exhibit identically stacked planes consisting of square planar coordinated M atoms (light gray) and [Ge]m zigzag chain pieces of varying lengths m. Each Ge atom is thereby coordinated by A atoms forming trigonal prisms (dark gray). The chain length m depends on the radius ratio rM4-/rA2+ (rr), whereat the M4- radius was estimated from the average Ca-M distances in the structures of Ca2M, which exhibit isolated tetrel anions. Depending on this radius ratio the structures of the title compounds feature [Ge]m chains of lengths m of 2, 4, 6 and infinite. Starting with Ge-Ge dumbbells in Ca2SnGe2 (rr= 1.57, space group P4/mbm, a= 748.58(13), c= 445.59)(8) pm, R1= 0.060, Mo2FeB2 type; cf. also Yb2SnGe2 [1], fig. top left), (Ca0.58Sr0.42)2SnGe2 shows Ge4 zigzag chain pieces (rr= 1.50, Pbam, a= 781.01(2), b= 1477.95(3), c= 457.00(1) pm, R1= 0.018, La2NiIn2 type; cf. also (Ca0.34Eu0.66)2PbGe2 [2], fig. bottom left). Ge6 pieces are present in (Ca0.23Sr0.77)2PbGe2 (rr= 1.48, Pbam, a= 2311.20(15), b= 791.64(5), c= 458.53(3) pm, R1= 0.073, new type, fig. top right) and infinit Ge chains in (CaxSr1-x)2PbGe2 (rr= 1.44-1.46, x= 0 to 0.22, Cmmm; for x= 0: a= 402.36(11), b= 1542.29(42), c= 463.27(10) pm, R1= 0.064, Mn2AlB2 type; cf. also (Sr0.21Eu0.79)2PbGe2 [2], fig. bottom right). In this series, i.e. with increasing m, the connectivity of M changes from a square planar coordination by four Ge in Ca2SnGe2 ([MGe4]) via [MGe3M] in (Ca0.58Sr0.42)2SnGe2 and [MGe3M]2[MGe2M2] in (Ca0.23Sr0.77)2PbGe2 up to [MGe2M2] in Sr2PbGe2, finally. The details of chemical bonding are discussed on the basis of band structure calculations.

Specific Peculiarities of the Electronic Structure of SrPb3Br8 As Evidenced from First-Principles DFT Band-Structure Calculations

2019 ◽  
Vol 48 (5) ◽  
pp. 3059-3068 ◽  
Author(s):  
O. Y. Khyzhun ◽  
V. L. Bekenev ◽  
N. M. Denysyuk ◽  
L. I. Isaenko ◽  
A. P. Yelisseyev ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
First Principles ◽  
Band Structure Calculations ◽  
Structure Calculations

Verbindungen mit Pentelid-Hanteln M2: AIII M6 und AII11M10 (A = Rb, Cs, Ba; M = Sb, Bi) / Compounds with Pentelide Dumbbells M2: AI11M6 and AII11M10 (A = Rb, Cs, Ba; M = Sb, Bi)

2004 ◽  
Vol 59 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Franziska Emmerling ◽  
Nina Längin ◽  
Frank Pickhard ◽  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Band Structure ◽  
Alkaline Earth ◽  
Major Change ◽  
Structure Type ◽  
Crystal Data ◽  
Compound I ◽  
Zintl Phase ◽  
Band Structure Calculations ◽  
Rich Side ◽  
Structure Calculations

Abstract The new ternary alkali pentelides A11M6 (A = Rb, Cs; M = Sb/Bi) all contain non electron-precise isolated dumbbells statistically composed of Sb/Bi. Their phase ranges as determined from single crystal data were found to be on the Sb-rich side of the overall composition A11Sb6−xBix in the case of the Rb compound (i. e. Rb11Sb5.4Bi0.6: orthorhombic Immm, a = 766.7(3), b = 1052.2(3), c = 1732.7(6) pm, Z = 4, R1 = 0.0554), and on the Bi-rich side of the overall composition A11Sb6−xBix in the case of A = Cs (i.e. Cs11Sb1.6Bi4.4). In the series of known alkaline earth compounds A11M10, containing pentelide dumbbells among isolated Zintl anions, a redetermination of the structure of Ba11Sb10 (orthorhombic, Immm, a = 1265.3(2), b = 1316.1(3), c =1947.2(5) pm, Z = 4, R1 = 0.0724) shows, that it represents a distorted variant of the tetragonal Ho11Ge10 structure type. This distortion is not only of crystallographic importance, as it results in a major change in the nature of the anions and their bonding, which is supported by DFT band-structure calculations. Likewise, the Zintl phase BaSb2 (monoclinic, P21/m, a = 1167.9(9), b = 438.1(5), c = 1257.1(9) pm, β = 100.53(2)°, Z = 6, R1 = 0.0648) crystallizes with a superstructure of the CaSb2-type previously reported.

Electronic structure ofNaxCu1−xIn5S8compounds: X-ray photoemission spectroscopy study and band structure calculations

2008 ◽  
Vol 78 (23) ◽  
Author(s):  
Catherine Guillot-Deudon ◽  
Sylvie Harel ◽  
Arezki Mokrani ◽  
Alain Lafond ◽  
Nicolas Barreau ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Photoemission Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray ◽  
Band Structure Calculations ◽  
Structure Calculations

The electronic structure of alkaline earth metal sulfides

1982 ◽  
Vol 23 (1) ◽  
pp. 68-71
Author(s):  
S. S. Mikhailova ◽  
G. V. Vol'f ◽  
I. V. Gribov ◽  
L. D. Finkel'shtein
Keyword(s):  
Electronic Structure ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Metal Sulfides ◽  
Alkaline Earth Metal

The electronic structure of disordered system

1964 ◽  
Vol 279 (1376) ◽  
pp. 82-97 ◽  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Density Of States ◽  
Disordered System ◽  
Perfect Lattice ◽  
Geometric Approximation ◽  
Band Structure Calculations ◽  
Interacting Electrons ◽  
Simplifying Assumptions ◽  
Structure Calculations

A general expression is written down for the density of states of non-interacting electrons in a disordered system. The expression is obtained on the basis of two simplifying assumptions; the geometric approximation, which is connected with the disorder, and an approximation concerning the potential which is commonly used in band structure calculations. In the case of a perfect lattice the result of Kohn & Rostoker (1954) for the band structure of the lattice is derived, and details of the density of states are available from the formula thus obtained. It is shown how the change in the energy of the electrons due to the presence of a phonon can be obtained.

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