F# version of sample from https://docs.microsoft.com/en-us/office/open-xml/how-to-create-a-spreadsheet-document-by-providing-a-file-name

gistfile1.txt

let CreateSpreadsheetWorkbook (filepath:string) =

	// Create a spreadsheet document by supplying the filepath.
	// By default, AutoSave = true, Editable = true, and Type = xlsx.
	let spreadsheetDocument:SpreadsheetDocument = SpreadsheetDocument.Create(filepath, SpreadsheetDocumentType.Workbook)

	// Add a WorkbookPart to the document.
	let workbookpart = spreadsheetDocument.AddWorkbookPart()
	workbookpart.Workbook <- new Workbook()
    
	// Add a WorksheetPart to the WorkbookPart.
	let worksheetPart = workbookpart.AddNewPart<WorksheetPart>()
	worksheetPart.Worksheet <- new Worksheet(new SheetData())

	// Add Sheets to the Workbook.
	let sheets = spreadsheetDocument.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());

	// Append a new worksheet and associate it with the workbook.
	let sheet = new Sheet
                    (
                        Id = new StringValue(spreadsheetDocument.WorkbookPart.GetIdOfPart(worksheetPart)), 
                        SheetId = UInt32Value.FromUInt32(1u), 
                        Name = new StringValue("mySheet")
                    )
	sheets.Append(sheet);

	workbookpart.Workbook.Save();

	// Close the document.
	spreadsheetDocument.Close();