Eu2PdH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one H(2), two equivalent H(3), and four equivalent H(1) atoms. In the second Eu site, Eu(2) is bonded in a 9-coordinate geometry to two equivalent H(3), three equivalent H(2), and four equivalent H(1) atoms. Pd(1) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Pd(1) atom. In the second H site, H(2) is bonded to one Eu(1), three equivalent Eu(2), and one Pd(1) atom to form a mixture of edge and corner-sharing HEu4Pd trigonal bipyramids. In the third H site, H(3) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HEu4Pd square pyramids.
Eu2PdH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one H(2), two equivalent H(3), and four equivalent H(1) atoms. The Eu(1)-H(2) bond length is 2.62 Å. Both Eu(1)-H(3) bond lengths are 2.71 Å. There are two shorter (2.71 Å) and two longer (2.90 Å) Eu(1)-H(1) bond lengths. In the second Eu site, Eu(2) is bonded in a 9-coordinate geometry to two equivalent H(3), three equivalent H(2), and four equivalent H(1) atoms. There is one shorter (2.56 Å) and one longer (2.59 Å) Eu(2)-H(3) bond length. There is one shorter (2.59 Å) and two longer (2.78 Å) Eu(2)-H(2) bond lengths. There are two shorter (2.46 Å) and two longer (2.67 Å) Eu(2)-H(1) bond lengths. Pd(1) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. The Pd(1)-H(2) bond length is 1.79 Å. The Pd(1)-H(3) bond length is 1.82 Å. Both Pd(1)-H(1) bond lengths are 1.76 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Pd(1) atom. In the second H site, H(2) is bonded to one Eu(1), three equivalent Eu(2), and one Pd(1) atom to form a mixture of edge and corner-sharing HEu4Pd trigonal bipyramids. In the third H site, H(3) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Pd(1) atom to form a mixture of distorted edge and corner-sharing HEu4Pd square pyramids.