digraph G {
    subgraph cluster1 {
        label = "ReagentnPreparationn(each position)";
        node [style=filled,color=white];
        style=filled;
        color=lightgrey;
        r0 [label="2D Reagent Multistructure File"];
        r1 [label= "3D Reagent Multistructure FilenNeutralized and Minimized"];
        r2 [label= "3D Reagent Multistructure FilenIonized and MinimizednGrownames AttachednIonized"];
        r0 -> r1 [label=" 2a: LigPrep"];
        r1 -> r2 [headport=nw,label=" 2b: LigPrep"];
        r2 -> r1 [tailport=ne,label=" 2c: Ligprep"];
    }
}