function createPhaseDiagram()
    % Define axis values
    SCATTERING_LENGTH_RANGE = [80.00 81.04 82.08 83.12 84.17 85.21 86.25 87.29 88.33 89.38 90.42 91.46 92.50 93.54 94.58 95.62 96.67 97.71 98.75 99.79 100.83 101.88 102.92 103.96 105.00];
    NUM_ATOMS_LIST = [100000 304167 508333 712500 916667 1120833 1325000 1529167 1733333 1937500 2141667 2345833 2550000 2754167 2958333 3162500 3366667 3570833 3775000 3979167 4183333 4387500 4591667 4795833 5000000];
    
    xlen = length(NUM_ATOMS_LIST);
    ylen = length(SCATTERING_LENGTH_RANGE);
    
    M    = zeros(xlen,ylen);  % Phase diagram matrix

    fig = figure('Name', 'Manual Phase Diagram Input', ...
                 'NumberTitle', 'off', ...
                 'KeyPressFcn', @keyCallback);

    hImg = imagesc(M);
    set(gca, 'YDir', 'normal');
    colormap(parula);
    colorbar;
    axis equal tight;
    xticks(1:xlen);
    yticks(1:ylen);
    xticklabels(string(NUM_ATOMS_LIST));
    yticklabels(string(SCATTERING_LENGTH_RANGE));
    xlabel('Number of Atoms');
    ylabel('Scattering Length (a0)');
    grid on;
    title('Click a cell to label it. Press "q" to quit.'); % Zero-temperature Phase Diagram

    set(fig, 'WindowButtonDownFcn', @clickCallback);
    uiwait(fig);  % Wait until user quits

    [filename, pathname] = uiputfile('phase_diagram_matrix.mat', 'Save Matrix As');
    if ischar(filename)
        save(fullfile(pathname, filename), 'M', 'SCATTERING_LENGTH_RANGE', 'NUM_ATOMS_LIST');
        disp(['Matrix saved to ' fullfile(pathname, filename)]);
    end

    function clickCallback(~, ~)
        C = get(gca, 'CurrentPoint');
        col = round(C(1,1));
        row = round(C(1,2));
        if row >= 1 && row <= ylen && col >= 1 && col <= xlen
            prompt = sprintf('Enter label for scattering length %.1f and N = %d:', ...
                             SCATTERING_LENGTH_RANGE(row), NUM_ATOMS_LIST(col));
            answer = inputdlg(prompt, 'Input Label', 1);
            if ~isempty(answer)
                val = str2double(answer{1});
                if ~isnan(val)
                    M(row, col) = val;
                    refreshDisplay();
                else
                    warndlg('Invalid input. Please enter a numeric value.', 'Invalid Input');
                end
            end
        end
    end

    function keyCallback(~, event)
        if strcmp(event.Key, 'q')
            uiresume(fig);
            close(fig);
        end
    end

    function refreshDisplay()
        set(hImg, 'CData', M);
        drawnow;
    end
end