Die Wechselwirkungen freier Elektronenpaare in Zintl-Phasen: Bandstruktur und Realraumanalyse descP124 Clathrat-Strukturtyps

Effects of morphology on the electronic and transport properties of Sn-based clathrates

“…The bond lengths in the 46-framework structure are longer than those in the 44 structure. This is due to occupation of antibonding orbitals in K 8 that this type of clathrate is not exclusively the domain of Sn compounds, 7,21,22 suggesting that the results here may be of more general utility. Type-III clathrates crystallize in the simple cubic P4 1 32 ͑Ref.…”

Band-structure calculations forBa6Ge25andZerec1, Yaresko2, Thalmeier3 et al. 2002Phys. Rev. B221372View full textAdd to dashboardCite

“…12 But, as was pointed out there, in Ba 6 Ge 21 In 4 this characteristic is absent due to a smaller spatial extension of germanium orbitals. We did not notice significant difference of DOS between three-bonded ͑Ge3, Ge5͒ and four-bonded germanium atomic spheres.…”

The Intrinsic Shape of the cubic cP124 Clathrate Structure

“…It is very important to note, that all Y nodes are collected around the large cavities centered at position 4a. Indeed, it was shown by Fässler [26] that the lone pairs of the Y nodes form a distorted cube and point toward 4a (section 4).…”

“…Therefore, the selected composition of the resulting phase seems to be another proof for the preference of electronically balanced valence compounds (Zintl phase with [In 4 Ge 21 ] 12Ϫ Z 108 e/f.u.). Later it was found that the complete balance is obviously not necessary to form this structure (Table 1), which can be varied from the electron- 16.300 4331 [25,26] Fig. 1 (bottom, left) and Fig.…”

“…Setting in space group P4 1 32 (No. 213 [4,10,11,17,16,18,21,22,24,25,26] deficient K 6 Sn 25 [25,26] via the electron-balanced Ba 6 In 4 Ge 25 [11], K 6 Bi 2 Sn 23 [26] or Na 3 Rb 5 Sn 25 [28] to the electron-excess Ba 6 Ge 25 [15Ϫ21] (for more details see 2.5). The unit cell contains Z ϭ 4 formula units (f.u.)…”