LC uses the range A11Z458 for the works themselves (collections, selections, individual works) and local practice has always followed this part of the table from the implementation of LC classification in the 1970's.
However, LC notation practice for items related to the literary works of the author is to assign numbers in the range Z4581Z9999. Prior to 2005, SML practice dating from the implementation of LC classification was to modify LC notation for single Cutter authors for biography/criticism, correspondence, and autobiography. Beginning in 2001, SML began to follow the standard LC notation practice for new authors. With the Feb. 2005 policy change the practice is now extended to previously established authors. The mapping of the number range is given in the LC PPZ40 table.
LC PPZ40 Table for authors (1 Cutter number)
Collected works Including collected works in specific genres 

PPZ40 .x date 
By date 
(PPZ40 .xA11.xA13) 
By editor 
Subarrangement by editor has been discontinued by the Library of Congress. Beginning in 2005, all collected works are subaaranged by date 

(PPZ40 .xA14.xA19) 
Collected prose, poetry, plays, etc. 
For collected genre see PPZ40 .x date 

Translations (Collected or selected) 

PPZ40 .xA199 
Modern versions of early authors in the same language. By date 
PPZ40 .xA1995 
Polyglot. By date 
PPZ40 .xA2 
English. By date 
PPZ40 .xA3 
French. By date 
PPZ40 .xA4 
German. By date 
PPZ40 .xA5A59 
Other. By language (alphabetically and date 
PPZ40 .xA6 
Selected works. Selections. By date 
PPZ40 .xA61.xZ458 
Separate work. By title 
Biography and criticism 

PPZ40 .xZ4581.xZ4589 
Periodicals. Societies. Serials 
PPZ40 .xZ459 
Dictionaries, indexes, etc. By date 
PPZ40 .xZ46 
Autobiography, journals, memoirs. By date 
PPZ40 .xZ48 
Letters (Collections). By date (Including collections of letters to and from particular individuals) 
PPZ40 .xZ5.xZ999 
General works 
Example demonstrating the application of PPZ40 are at: PPZ40 Examples
Since there appears to be no documentation on how LC expands Z Cutters used in table PPZ40, ideally, you would shelflist works of biography, criticism, correspondence, autobiography, etc. (Z4581Z9999) against the LC Online catalog. While this was the earlier recommendation, since we now accept inconsistencies in the book number order, for efficiency you should either shelflist the number against the book number file in Orbis, or construct a 3 digit number based on our unofficial Z notation table (see below). Keep in mind that the number must be within the Z4581Z9999 range.
Scenario:
 Book about D.H. Larence. No 050 00:
100 
1 
$a Hostettler, Maya, $d 1954 

245 
1 
4 
$a D.H. Lawrence, travel books and fiction / $c Maya Hostettler. 
261 
4 
$a Berne ; $a New York : $b P. Lang, $c 1985. 

600 
1 
0 
$a Lawrence, D. H. $q (David Herbert), $d 18851930 $x Criticism and interpretation. 
 Determine the class/author Cutter number. Both Yale and LC use PR6023.A93
c1. Option A: If you prefer to shelflist the Z number in the existing file, open the Orbis OPAC and select the search index (the Search in: box) for Call Number (LC). You will get a better overview of the Zs by using the OPAC. Keeping in mind that the range of biography/criticism is limited to Z4581Z999x, do a search truncated to the lower limit: pr6023.a93 z458
You need to insert Hostettler's number between the numbers for GrimmHorlacher [Z63112] and Lawrence [Z642]. Be sure to leave enough room for future numbersending the number with 2 could make things rather tight.
Perhaps: PR6023.A93 Z635
c2. Option B. Construct the Z number using the unofficial Z expansion table below without consulting the online sequence in the OPAC. Main entry: Hostettler.Initial letter H is in the range Z64Z68. H is roughly in the middle of the range: Z66. An additional digit for the second letter “o” corresponds to 6 in the expansion column. Based on the table, the number constructed would be around: PR6023.A93 Z666. Since we are accepting member library book numbers without shelflisting, it is understood that the sequence will not be consistent.
Unofficial Z expansion table
Z5Z999 expansion on first letter of main entry (Criticism and biography 
LC expansion on 2nd letter and following letters 

AE 
Z54Z58 
AD 
3 
FJ 
Z64Z68 
EH 
4 
KO 
Z74Z78 
OL 
5 
PT 
Z84Z88 
MO 
6 
UZ 
Z94Z99 
PS 
7 
TV 
8 

WZ 
9 
Another (madeup) example: A biography of Michael Connelly:
100 
1 
$a Thurston, Patricia. 

245 
1 
4 
$a Mean streets of Los Angeles / $c Patricia Thurston. 
261 
4 
$a Los Angeles : $b Press of the University of California, $c 2013. 

600 
1 
0 
$a Connelly, Michael, $d 1956 $x Criticism and interpretation. 
 LC author number is: PS3553.O51165; decision is to construct the Z number
 Book number. Main entry Thurston, first letter T. Table assigns Z84Z88 to the range PT, so number should begin with Z88. Then expand for second letter H. Table assigns 4 to expansion letters in the range EH, so Z884:
050 
4 
$a PS3553.O51165 $b Z884 2013 