Database of Disordered Zeolite Structures

Intergrowth Family **Beta**

Periodic Building Unit

Periodic Building Unit (PerBU): | beta layer | ||

Layer symmetry | P (-4) m 2 | ||

Connectivity pattern

Examples |

The layers are stacked along the [001] direction using the following connectivity patterns

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^{*} relative to the previous layerShort explanation:The "purple layer" is a mirror image of the previous layer (symmetry operation m) and is translated 1/3 of a unit cell along . aNote: The next layer cannot be translated along the same axis, e.g. a "purple" layer can only be followed by a yellow, blue or green layer.Detailed Explanation:Each application of a mirror operation changes the pattern of the connecting T atoms. If they form rows along the direction on the top surface of the previous layer, only translations of zero (green layer) or ±1/3 a (purple or brown layer) are possible. If they form rows along the a direction (gray spheres), only translations of zero (green layer) or ±1/3 b (yellow or blue layer) are possible. The connecting T atoms (those pointing up) from the top surface of the previous layer (gray layers) are highlighted as spheres in the examples to the right.b |

Effect on channel system | |

The disorder does not block the channel system |

Simplest ordered end members

The color of each layer reflects the symmetry/translation operation used to generate it from the previous layer (see table above).

Polymorph Beta_A | |||||

Cell Parameters: | tetragonal | P 4_{1} 2 2: (# 91) |
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a = 12.6614 Å |
b = 12.6614 Å |
c = 26.4061 Å |
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α = 90.0000° | β = 90.0000° | γ = 90.0000° | |||

Volume = | 4233.2 Å^{3} |
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Framework Density (FD_{Si}): |
15.1 |

Ring sizes (# T-atoms): | 12 6 5 4 | ||

Channel dimensionality: | Topological (pore opening > 6-ring): 3-dimensional |

Maximum diameter of a sphere: | |||||||

that can be included | 6.59 Å | ||||||

that can diffuse along | a: 5.94 Å | b: 5.94 Å | c: 5.94 Å | ||||

addional volume data |

Composite Building Units: |

mor | bea | mtw | ||||

Beta_A is chiral and has an enantiomer with the space group 4_{3} 2 2In this space group and setting, the PerBUs are stacked along [001] |

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

Polymorph Beta_B | |||||

Cell Parameters: | monoclinic | C 1 2/c 1: (# 15) | |||

a = 17.8965 Å |
b = 17.9200 Å |
c = 14.3282 Å |
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α = 90.0000° | β = 114.8030° | γ = 90.0000° | |||

Volume = | 4171.3 Å^{3} |
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Framework Density (FD_{Si}): |
15.3 |

Ring sizes (# T-atoms): | 12 6 5 4 | ||

Channel dimensionality: | Topological (pore opening > 6-ring): 3-dimensional |

Maximum diameter of a sphere: | |||||||

that can be included | 6.82 Å | ||||||

that can diffuse along | a: 5.88 Å | b: 5.88 Å | c: 5.88 Å | ||||

[1 1 0] : 6.23 Å | |||||||

addional volume data |

Composite Building Units: |

mor | bea | mtw | ||||

In this space group and setting, the PerBUs are stacked along [001] |

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

Polymorph Beta_CH | |||||

Cell Parameters: | monoclinic | P 1 2/c 1: (# 13) | |||

a = 12.2815 Å |
b = 12.2847 Å |
c = 27.4117 Å |
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α = 90.0000° | β = 107.2880° | γ = 90.0000° | |||

Volume = | 3948.9 Å^{3} |
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Framework Density (FD_{Si}): |
16.2 |

Ring sizes (# T-atoms): | 12 6 5 4 | ||

Channel dimensionality: | Topological (pore opening > 6-ring): 3-dimensional |

Maximum diameter of a sphere: | |||||||

that can be included | 6.46 Å | ||||||

that can diffuse along | a: 5.3 Å | b: 5.69 Å | c: 5.3 Å | ||||

addional volume data |

Composite Building Units: |

mor | bea | mtw | ||||

In this space group and setting, the PerBUs are stacked along [001] Beta_CH is an ordered intergrowth of Beta_A and Beta_B |

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

Polymorph BEC | |||||

Cell Parameters: | tetragonal | P 4_{2}/m m c: (# 131) |
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a = 12.7690 Å |
b = 12.7690 Å |
c = 12.9770 Å |
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α = 90.000° | β = 90.000° | γ = 90.000° | |||

Volume = | 2115.9 Å^{3} |
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Framework Density (FD_{Si}): |
15.1 |

Ring sizes (# T-atoms): | 12 6 5 4 | ||

Channel dimensionality: | Topological (pore opening > 6-ring): 3-dimensional |

Maximum diameter of a sphere: | |||||||

that can be included | 6.95 Å | ||||||

that can diffuse along | a: 6.09 Å | b: 6.09 Å | c: 6.09 Å | ||||

addional volume data |

Composite Building Units: |

mor | d4r | mtw | ||||

In this space group and setting, the PerBUs are stacked along [001] Beta_CH is an ordered intergrowth of Beta_A and Beta_B |

Note: This polymorph corresponds to the ordered framework BEC | |

Disorder Example

There is no blocking of the 3D channel system. |