From caa92f8b8543af897c1c7e9d38e3b0209eaff408 Mon Sep 17 00:00:00 2001 From: "James.Hester" Date: Wed, 13 Sep 2023 16:42:51 +1000 Subject: [PATCH 1/5] Add new UNI symbols. --- cif_mag.dic | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) diff --git a/cif_mag.dic b/cif_mag.dic index d37e134..cba491a 100644 --- a/cif_mag.dic +++ b/cif_mag.dic @@ -2732,6 +2732,71 @@ save_space_group_magn.name_og save_ +save_space_group_magn.name_uni + + _definition.id '_space_group_magn.name_UNI' + _definition.update 2023-06-01 + _description.text +; + The Unified (UNI) symbol for a MSG is an improvement of the + corresponding BNS symbol, and is therefore associated with a BNS + setting of the MSG, but also captures some essential features of + the OG symbol. See the entries on _space_group_magn.name_BNS and + _space_group_magn.name_OG for more information about those symbols. + Like the BNS symbol, the UNI symbol of an MSG is based on the symbol + of a non-magnetic space group F (for types 1-3) or of an index-2 + subgroup D of F (for type4). The UNI symbol of a type-3 MSG is + identical to the corresponding BNS and OG symbols. + + The time-reversal group consists of the identity operation 1 + and the time-reversal operation 1’. For type-1, type-2, and + type-4 MSGs, the appropriate generator of the time-reversal group + is always explicitly displayed after the space-group generators + of F, and separated from the generators of F by a dot ("."). + Furthermore, for a type-4 MSG, the anti-translation subscript is + attached to the 1’ generator at the end of the UNI symbol rather + than to the lattice symbol at the front, and always conveys an + unambiguous translation. + + The complete UNI symbol of a type-4 MSG includes the symbol of + space group F in square brackets at the end. In the extension, + the symbol of F is presented in same BNS setting used for subgroup + D in the main part of the UNI symbol, when possible, or else in a + setting rotated by 45 degrees relative to the BNS setting of D. + + The UNI MPG symbol is obtained directly from the truncated UNI MSG + symbol by dropping the lattice symbol at the front, eliminating any + subscripts, and replacing each glide-plane symbols with mirror-plane + symbol "m". The explicit presence of the time-reversal generator at + the end of the UNI symbol of a type-4 MSG makes it clear that the + MPG is of type 2 (grey). + + Analogous tags: symCIF:_space_group.name_H-M_ref + + Ref: Campbell et al., Acta Cryst. A78, 99–106 (2022). + ISO-MAG tables of H.T. Stokes and B.J. Campbell at http://iso.byu.edu +; + _name.category_id space_group_magn + _name.object_id name_UNI + _type.purpose Encode + _type.source Recorded + _type.container Single + _type.contents Text + + loop_ + _description_example.case + "P1.1" + "P1.1'" + "P1.1'_c[P1] or P1.1'_c" + "P-1.1" + "P-1.1'" + "P-1'" + "P-1.1'_c[P-1] or P1.1'_c" + "P2.1'_C[C2] or P2.1'_C" + "Ia'-3d'" + +save_ + save_space_group_magn.number_bns _definition.id '_space_group_magn.number_BNS' @@ -2855,6 +2920,60 @@ save_space_group_magn.point_group_name save_ +save_space_group_magn.point_group_name_uni + + _definition.id '_space_group_magn.point_group_name_UNI' + _definition.update 2023-06-01 + _description.text +; + Any magnetic point group (MPG) can be constructed by starting + with a non-magnetic point group P, and then by adding a time-reversal + component to some or all or none of its elements. For a + type-1 MPG, M = P, there are no time-reversed elements. For a + type-2 MPG, M = P + P1', there is both a time-reversed and a + non-time-reversed copy of each element in P. For a type-3 MPG, + M = Q + (P - Q)1', there is a subgroup Q of P of index 2 whose + elements are not time reversed, whereas the remaining elements + in P-Q are time reversed. + + The time-reversal group consists of the identity operation 1 + and the time-reversal operation 1’. The UNI symbol of a MPG is a slight + modification of the earlier H-M MPG symbol, and only differs from + the H-M MPG symbol for type-1 and type2 MPGs, so that the + the appropriate generator of the time-reversal group + is always explicitly displayed after the space-group generators + of P, and separated from the generators of P by a dot ("."). + For a type-1 MPG or type-2 MPG, the UNI symbol is that of + non-magnetic point group P, followed by ".1" or ".1’", respectively. + For a type-3 MPG, the UNI MPG symbol is that of P with a prime added to each + time-reversed generator. + + Analogous tags: symCIF:_space_group.point_group_H-M + + Ref: 'Magnetic Group Tables' by D.B. Litvin at + http://www.iucr.org/publ/978-0-9553602-2-0 + Campbell et al., Acta Cryst. A78, 99–106 (2022). +; + _name.category_id space_group_magn + _name.object_id point_group_name_UNI + _type.purpose Encode + _type.source Recorded + _type.container Single + _type.contents Text + + loop_ + _description_example.case + 1.1 + 1.1' + -1.1 + -1.1' + -1' + 4mm.1 + 4'm'm + 4'mm' + +save_ + save_space_group_magn.point_group_number _definition.id '_space_group_magn.point_group_number' From 1477c42c67c6547137680f1aefe7a85275365a06 Mon Sep 17 00:00:00 2001 From: James Hester Date: Fri, 1 Dec 2023 13:00:40 +1100 Subject: [PATCH 2/5] Correct indefinite article Co-authored-by: Antanas Vaitkus --- cif_mag.dic | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cif_mag.dic b/cif_mag.dic index cba491a..f3fb9ea 100644 --- a/cif_mag.dic +++ b/cif_mag.dic @@ -2738,7 +2738,7 @@ save_space_group_magn.name_uni _definition.update 2023-06-01 _description.text ; - The Unified (UNI) symbol for a MSG is an improvement of the + The Unified (UNI) symbol for an MSG is an improvement of the corresponding BNS symbol, and is therefore associated with a BNS setting of the MSG, but also captures some essential features of the OG symbol. See the entries on _space_group_magn.name_BNS and From e9d9ff1565a90c7775c67a5f723d48ed56896857 Mon Sep 17 00:00:00 2001 From: James Hester Date: Fri, 1 Dec 2023 13:00:52 +1100 Subject: [PATCH 3/5] Correct indefinite article Co-authored-by: Antanas Vaitkus --- cif_mag.dic | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cif_mag.dic b/cif_mag.dic index f3fb9ea..038320b 100644 --- a/cif_mag.dic +++ b/cif_mag.dic @@ -2937,7 +2937,7 @@ save_space_group_magn.point_group_name_uni in P-Q are time reversed. The time-reversal group consists of the identity operation 1 - and the time-reversal operation 1’. The UNI symbol of a MPG is a slight + and the time-reversal operation 1’. The UNI symbol of an MPG is a slight modification of the earlier H-M MPG symbol, and only differs from the H-M MPG symbol for type-1 and type2 MPGs, so that the the appropriate generator of the time-reversal group From 9358c6c751509d57cb4116aaa488daa274ae7cf0 Mon Sep 17 00:00:00 2001 From: James Hester Date: Fri, 1 Dec 2023 13:01:32 +1100 Subject: [PATCH 4/5] Remove stray word Co-authored-by: Antanas Vaitkus --- cif_mag.dic | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cif_mag.dic b/cif_mag.dic index 038320b..26d952f 100644 --- a/cif_mag.dic +++ b/cif_mag.dic @@ -2939,7 +2939,7 @@ save_space_group_magn.point_group_name_uni The time-reversal group consists of the identity operation 1 and the time-reversal operation 1’. The UNI symbol of an MPG is a slight modification of the earlier H-M MPG symbol, and only differs from - the H-M MPG symbol for type-1 and type2 MPGs, so that the + the H-M MPG symbol for type-1 and type2 MPGs, so that the appropriate generator of the time-reversal group is always explicitly displayed after the space-group generators of P, and separated from the generators of P by a dot ("."). From da25fdbae6ac19a02229e214d70cd83f35ef3f6c Mon Sep 17 00:00:00 2001 From: James Hester Date: Fri, 1 Dec 2023 13:02:00 +1100 Subject: [PATCH 5/5] Add alternate sources for the same reference. Co-authored-by: Antanas Vaitkus --- cif_mag.dic | 2 ++ 1 file changed, 2 insertions(+) diff --git a/cif_mag.dic b/cif_mag.dic index 26d952f..8074a8b 100644 --- a/cif_mag.dic +++ b/cif_mag.dic @@ -2953,6 +2953,8 @@ save_space_group_magn.point_group_name_uni Ref: 'Magnetic Group Tables' by D.B. Litvin at http://www.iucr.org/publ/978-0-9553602-2-0 Campbell et al., Acta Cryst. A78, 99–106 (2022). + https://doi.org/10.1107/S2053273321012912 + https://www.iucr.org/paper?ib5106 ; _name.category_id space_group_magn _name.object_id point_group_name_UNI