Ba2PdH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 5-coordinate geometry to one H(2), two equivalent H(1), and four equivalent H(3) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to two equivalent H(1), three equivalent H(2), and four equivalent H(3) atoms. Pd(1) is bonded in a tetrahedral geometry to one H(1), one H(2), and two equivalent H(3) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HBa4Pd square pyramids. In the second H site, H(2) is bonded to one Ba(1), three equivalent Ba(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HBa4Pd trigonal bipyramids. In the third H site, H(3) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Pd(1) atom.
Ba2PdH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 5-coordinate geometry to one H(2), two equivalent H(1), and four equivalent H(3) atoms. The Ba(1)-H(2) bond length is 3.08 Å. Both Ba(1)-H(1) bond lengths are 2.92 Å. There are two shorter (2.95 Å) and two longer (3.11 Å) Ba(1)-H(3) bond lengths. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to two equivalent H(1), three equivalent H(2), and four equivalent H(3) atoms. There is one shorter (2.88 Å) and one longer (2.92 Å) Ba(2)-H(1) bond length. There is one shorter (2.84 Å) and two longer (2.97 Å) Ba(2)-H(2) bond lengths. There are two shorter (2.78 Å) and two longer (2.90 Å) Ba(2)-H(3) bond lengths. Pd(1) is bonded in a tetrahedral geometry to one H(1), one H(2), and two equivalent H(3) atoms. The Pd(1)-H(1) bond length is 1.80 Å. The Pd(1)-H(2) bond length is 1.79 Å. Both Pd(1)-H(3) bond lengths are 1.79 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HBa4Pd square pyramids. In the second H site, H(2) is bonded to one Ba(1), three equivalent Ba(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HBa4Pd trigonal bipyramids. In the third H site, H(3) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Pd(1) atom.