HPM-18: DO Family

Periodic Building Unit (PerBU):

Layer symmetry

2D cell parameters

a = 10.18 Å

b = 14.61 Å

gamma = 90°

To facilitate understanding of the connectivity patterns shown below, the O atoms that connect to the two rows of d4r units have been highlighted in the HEI layer shown to the right.

Intergrowth Family HPM-18

2-dimensional disorder of the units connecting ordered layers

Periodic Building Unit

Connecting unit

	Connecting unit	d4r

References


		Yu, H., Zhang, Z., Li, J., Balestra, S.R.G., Rei Gao, Z. and Camblor, M. A.
			"Unexpected Phase Selectivity in Germanosilicate Zeolite Synthesis: Discovery and Structure of HPM-18, a Novel Stable d4r- Containing Structure"
			Journal of Materials Chemistry A, , (2026)

Connectivity pattern

The HEI layers are arranged in an ordered fashion, with each layer being related to the previous one by a translation of 1/2b. However, the double rows of d4r unit connectors can be disordered along both b and c, making the disorder in this family 2-dimensional.

Examples

Positions of d4r unit connectors in a row
There are double rows of d4r connectors above the HEI layer that can be arranged in four different ways. The position of the first d4r unit (along a) determines the positions of all the other d4r units in that row.

Row 1 (ca 1/4 b)	Row 2 (ca 1/4 b)	Comment	Image
0a	0a	Connection type 1
0a	1/2a	Connection type 2
1/2a	0a	Connection type 3
1/2a	1/2a	Connection type 4

Examples

Disorder along b: layers formed by the rows of d4r unit connectors
The arrangement of the rows of d4r units is not necessarily periodic along b. Each row is independent of the next. For example, starting with Connection type 1, there are four possibilities for the next set of connecting d4r units in the layer.

First Connection Type	Next Connection Type	Comment	Image
1	1	Second set of connectors shifted by 1b^*
1	2	Second set of connectors shifted by 1b^*
1	3	Second set of connectors shifted by 1b^*
1	4	Second set of connectors shifted by 1b^*

^* relative to the previous row of connectors


Polymorph HPM-18_A

Cell Parameters:	orthorhombic	P n c 2 (# 30)
	a = 10.3009 Å	b = 14.8342 Å	c = 37.1791 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	5681.2 Å³
Framework Density (FD_Si):	16.9

	Ring sizes (# T atoms):	12 10 9 8 7 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional

Maximum diameter of a sphere:
	that can be included	5.78 Å
	that can diffuse along	a: 4.73 Å	b: 3.94 Å	c: 3.47 Å
		addional volume data

Composite Building Units:

NONE

In this space group and setting, the ordered connecting d4r rows are along [100] and the layers are stacked along [001]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph HPM-18_B

Cell Parameters:	triclinic	P 1 (# 1)
	a = 39.6161 Å	b = 10.0621 Å	c = 14.8410 Å
	α = 89.4300°	β = 111.7200°	γ = 90.0750°
	Volume =	5495.6 Å³
Framework Density (FD_Si):	17.5

	Ring sizes (# T atoms):	12 10 9 8 7 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional

Maximum diameter of a sphere:
	that can be included	5.7 Å
	that can diffuse along	a: 3.31 Å	b: 4.69 Å	c: 3.61 Å
		addional volume data

Composite Building Units:

NONE

In this space group and setting, the ordered connecting d4r rows are along [010] and the layers are stacked along [100]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph HPM-18_C

Cell Parameters:	monoclinic	C 1 2 1 (# 5)
	a = 17.9638 Å	b = 37.2767 Å	c = 10.3099 Å
	α = 90.0000°	β = 124.4110°	γ = 90.0000°
	Volume =	5695.7 Å³
Framework Density (FD_Si):	16.8

	Ring sizes (# T atoms):	12 10 9 8 7 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional

Maximum diameter of a sphere:
	that can be included	5.73 Å
	that can diffuse along	a: 3.98 Å	b: 3.35 Å	c: 4.8 Å
		addional volume data

Composite Building Units:

NONE

In this space group and setting, the ordered connecting d4r rows are along [001] and the layers are stacked along [010]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph HPM-18_D

Cell Parameters:	orthorhombic	P n a 2₁ (# 33)
	a = 10.0730 Å	b = 14.7297 Å	c = 36.9191 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	5477.8 Å³
Framework Density (FD_Si):	0.0

	Ring sizes (# T atoms):	12 9 8 7 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional

Maximum diameter of a sphere:
	that can be included	5.36 Å
	that can diffuse along	a: 4.71 Å	b: 3.33 Å	c: 3.33 Å
		addional volume data

Composite Building Units:

NONE

In this space group and setting, the ordered connecting d4r rows are along [100] and the layers are stacked along [001]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph HEI

Cell Parameters:	monoclnic	C 1 2/c 1 (# 15)
	a = 36.7640 Å	b = 14.6100 Å	c = 10.1890 Å
	α = 90.000°	β = 105.641°	γ = 90.000°
	Volume =	5556.5 Å³
Framework Density (FD_Si):	17.6

	Ring sizes (# T atoms):	12 8 7 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 3-dimensional

Maximum diameter of a sphere:
	that can be included	5.38 Å
	that can diffuse along	a: 3.41 Å	b: 3.41 Å	c: 4.81 Å
		addional volume data

Composite Building Units:


	d4r (t-cub )

In this space group and setting, the ordered connecting rows are along c and the layers are stacked along [100]

	Note: This polymorph corresponds to the ordered framework HEI